# Ferrum-Qt capability matrix

## Current boundary

This is the authoritative current-product ledger. It records what the ordinary
`ferrum-qt` desktop application supports, refuses, drops before production, or
leaves for a later designed contract. It is not a port-all checklist for the
historical BKChem catalog.

The 2026-08-15 retirement removed the explicit compatibility host and its OASA
session, action, mode, worker, codec, and projection island. The ordinary
`MainWindow` is the only desktop route, and production dependency declarations
no longer require OASA. The isolated oracle remains migration evidence only; it
is not a runtime fallback.

The categories have precise meanings:

- **Supported**: a bounded user workflow is owned by Rust/Ferrum plus its thin
  Qt client. A row may name deliberately bounded facts; unlisted variants are
  not implied.
- **Refused with recovery**: the ordinary product declines an input before
  parsing or mutation and provides the named safe next step where one exists.
- **Preproduction drop**: no current product owner exists. Reintroducing it
  requires a new user-facing contract rather than reviving historical code.
- **Future contract**: a useful possible capability whose requirements are not
  yet designed or accepted.

Permanent tests cover compact, deterministic native behavior that can plausibly
regress. Local staged-runtime rebuilds, ordinary-window walkthroughs, source and
inventories, accessibility and visual review, and race observations are
one-time implementation evidence. This ledger creates no byte, pixel, timing,
network, fixture, menu-inventory, or source-count gate.

## Current capability ledger

| ID | Capability | Disposition and owner | Current boundary |
| --- | --- | --- | --- |
| FQ-001 | Application and tabs | Supported: `ferrum_qt` ordinary `MainWindow` with Rust document sessions. | Create, close, bootstrap, Recent, and explicitly targeted current-tab Open retain tab and stale/busy containment. |
| FQ-002 | CDML and decoded CD-SVG files | Supported: Rust local-document ingress/publication with native Qt file clients. | Open/save/Save As/close/Recent/recovery support bounded CDML; a decoded CD-SVG `.svg` becomes a clean Save-As-only CDML document while retaining source provenance. |
| FQ-002 update | CML/CML2 File/Open and CLI conversion output | Supported as two bounded Rust-owned profiles. | Valid closed-profile CML/CML2 opens into one clean new native tab while preserving the bootstrap tab. Separately, `ferrum convert --to cml|cml2` emits canonical CML2; `cml1` is input-only. Direct CML conversion preserves validated molecule/atom IDs and record order, while generic conversion refuses facts outside the lossless CML2 profile. This adds no current-tab replacement, append, generic interchange importer, Qt CML export, CML document model, or CDML save baseline. |
| FQ-002a | CDXML simple-molecule File/Open | Supported: the Rust CDXML decoder, document interchange admission, mandatory native render preflight, and the thin Qt File/Open client. | Bounded input-only `.cdxml` creates one clean new tab with typed CDXML provenance, reallocated durable IDs, and no source save baseline. The decoder accepts direction-free single-bond `Display="Wavy"`, `Display="Bold"`, and `Display="Dash"`; the document's sole `DocumentBondPresentationV1` lowers them to canonical CDML `s1`, `b1`, and `d1`, and the Rust renderer must produce one issue-free plan before Qt publishes the tab. First Save or Save As writes CDML. Unsupported chemistry or presentation, directional styled bonds, namespaces, and malformed or over-budget input refuse without mutating the active document. `ferrum convert` refuses CDXML before source read because the descriptor admits it only for new-document Open. |
| FQ-002b | Other local document formats | Refused with recovery: suffix-only native Qt refusal before document work. | CDX, `.cdsvg`, `.svgz`, compressed CDML, and compressed SVG do not parse, decompress, mutate a tab, or invoke a fallback. `Recovery Export CDML...` writes a recovery copy of the current supported document; it is not a converter. |
| FQ-003 | CDML projection and opaque facts | Supported: Rust typed document/session/projection boundary. | The native path owns typed facts, rendering observations, and bounded opaque preservation. Lexical XML fidelity is not promised. |
| FQ-004 | Chemistry import | Supported: Rust chemistry/document import plus native Qt clients. | SMILES, representable InChI, V2000/V3000 Molfile, and bounded 2D SDF import through one authenticated native operation. This does not subsume FQ-002's separate CML/CML2 new-document profile. Unsupported chemistry fails visibly without partial insertion. |
| FQ-005 | Molecule file export | Supported: Rust chemistry/document export plus safe native publication. | Selected supported direct roots export as Molfile, one-record SDF, SMILES, or Standard/Fixed-H InChI without mutating the document. Two or more distinct direct roots also export as one atomic multi-record SDF V2000 or V3000 file through the CLI and explicit Qt actions; Rust defines record order. Unrepresentable variants remain future contracts. |
| FQ-006 | Whole-document artifact export | Supported: Rust Render Plan V2 backends and descriptor-relative publisher with a native Qt client. | `Export...` produces complete SVG, vector PDF, or transparent PNG at one pixel per Rust page point. Immutable provenance fences, source/known-hardlink protection, quiet cancel, and complete-plan refusal are part of the behavior. |
| FQ-007 | Basic drawing, rings, and paths | Supported in accepted bounded Rust-owned Qt slices. | The ordinary editor authors supported atoms, normal bonds, directed stereobonds, detached saturated-carbon C3-C8 regular rings through Edit > `Insert Regular Ring...`, the shared C6 `Insert Cyclohexane Ring` shortcut, `CurvedElectronArrowV1`, `CurvedRetroArrowV1`, `CurvedNormalReactionArrowV1`, `CurvedEquilibriumArrowV1`, Polyline, and Polygon. Each regular ring uses the existing Rust-owned `DocumentOperationV1` prepare/commit transition, so Rust retains topology, geometry, durable CDML facts, renderer admission, history, Undo/Redo, and typed no-mutation refusal behavior; Qt owns only the closed chooser and click handoff. Escape disarms without mutation; an occupied placement is nonmutating and retains an armed retry. If an accepted mutation cannot refresh its presentation, the durable result remains pending while Qt retires the gesture and directs the author to refresh before saving or editing. `Draw Polyline` and `Draw Polygon` use one opaque Rust point-at-a-time lifecycle: accepted points are durable, optional hover is display-only, and Rust derives overlay geometry and appearance, validates, preflights, fences, and commits atomically. Qt owns scene conversion, events, and user wording; its transient accepted-press coordinate exists only to de-duplicate real/QTest double-click delivery. The full-vector preview bridge is retired. The curved-arrow records accept only ordered `start`/`control`/`end` points. Electron, retro, and curved normal share Rust terminal geometry; equilibrium uses Rust's distinct two-lane/head DTO. Generic spline, head/property, association, and factory facts; ring fusion, arbitrary ring controls, and other presentation grammars remain future contracts. Directed direct-bond authoring is specified in FQ-007c. |
| FQ-007a | Atom and bond edits | Supported in accepted bounded slices: Rust revision-bound patches with native action and dialog clients. | `Change Element` accepts exactly one durable selected atom and commits only Rust-owned `set_atom_element`; its replacement projection restores that exact durable selection after one typed refresh recovery. Bond Properties is a closed presentation patch: Normal (`n1`, `n2`, `n3`), Wedge (`w1`), Hashed wedge (`h1`), Haworth front edge (`q1`), Bold (`b1`), Dashed (`d1`), and Wavy (`s1`). All non-normal choices are fixed single bonds; Qt offers no Adder or Dotted authoring/fallback path and emits one native presentation change rather than independent order/style edits. Rust owns applicability, durable validation, renderer preflight, atomic commit, history, and typed refusal. Atom numbers, deletes, Undo/Redo, and save/reopen remain native. A source fact outside an accepted grammar is retained only for read-only diagnostics or refused; it is never locally edited. A generic atom-property editor and broader direct-bond workflows require separate plans. |
| FQ-007b | Direct normal-bond drawing | Supported in one bounded Rust-owned Qt profile: pure admission plus opaque receipt commit for `ExistingExisting`, `ExistingNew`, `NewExisting`, and `NewNew` endpoint forms. | The Qt `Draw Bond` QAction and viewport gesture use the visible Next Drawing normal order (single, double, or triple) and redeem one Rust-issued receipt. New endpoints are intentionally fixed to carbon; `NewNew` authors a blank-canvas C-C molecule. Escape after admission leaves no commit. Rust owns candidate chemistry, identity allocation, fencing, history, and the sole commit. Wedges, aromatic bonds, free-form element selection, richer drawing interactions, and complete OASA/BKChem parity remain future work. |
| FQ-007c | Directed stereobond drawing and reversal | Supported: unversioned Rust/PyO3 pointer capability and bounded native Qt actions. | `Draw Solid Wedge Bond` and `Draw Hashed Wedge Bond` begin a direct-bond gesture, resolve its endpoint, prepare the generic `PreparedSessionTransitionV1`, then generically commit that one-use transition. Qt owns finite viewport-to-scene conversion, pointer events, and exact `none`/unique/ambiguous hit evidence. `ferrum-document-render` resolves the UI probe and one-use authoring capability. `ferrum-document` owns the durable `CreateDirectBondV1` request and generic transition, including nearest tolerance, ties, hit-ID validation, snap/new selection, all `ExistingExisting`/`ExistingNew`/`NewExisting`/`NewNew` forms, fences, candidate construction, renderer preflight, and required immutable operations. V1 applies only to durable document, fence, presentation, snap, and transition values where it is the actual contract version. The separate public `ferrum-document` neutral seam is native-Rust-only programmatic mutation using already-resolved durable IDs or finite new-atom points. It has no Qt/PyO3 route and accepts no pointer, viewport, hit, snap, overlay, render-plan, or issued-operation input. The authoring actions are bounded to Normal/Solid wedge/Hashed wedge; solid and hashed actions admit only covalent single `w1`/`h1` records whose pointer start is durable CDML tip and end is base. Edit > `Reverse Selected Wedge Direction` is enabled only for exactly one selected direct `w1` or `h1` bond. Rust validates the fenced source-ID operation, swaps only its ordered endpoints, and preserves the bond's durable object ID, unordered connectivity, type, selection, history, and persistence; unsupported style, malformed target, ambiguous target, and stale fence refuse atomically. Structural selection stays durable-ID based. The source ID is only the operation-factory input, while each visible wedge publishes one semantic Bond target with a renderer-derived path/line envelope and no structural child `DisplayOnly` sibling. The coalesced selection refresh timer is a single-shot child of the tab widget it queries. Probe errors and post-resolution refusals are distinct typed nonmodal recoveries; same existing atom is `self_loop` / `adjust_endpoint`, while `UnrenderableCandidate` is `ChangePresentation`. Escape and refusals are mutation-free. Bond Properties uses the same closed presentation vocabulary recorded in FQ-007a; it is not an alternate direct-bond authoring route. Generic stereo/CIP or E/Z semantics, inference, arbitrary styles/orders, and stereo import/export expansion remain separate work. |
| FQ-008 | SMILES and InChI | Supported: Rust chemistry boundary with native import/export clients. | The supported graph subset reads SMILES/InChI and copies or publishes canonical SMILES and Standard/Fixed-H InChI. Stereo and other unrepresentable facts are refused. |
| FQ-009 | Coordinates and parsed insertion | Supported: Rust chemistry preparation and authenticated document insertion. | Parsed supported graphs receive native coordinates and one atomic insertion; placement respects document provenance. |
| FQ-010 | Chemistry tools and fragments | Supported in bounded slices: Rust inspection, naming, linear-form, bond-capacity, explicit fragments, M4 structure diagnostics, and current-document SMARTS. | `Check Structure...` captures a fenced snapshot and selected direct roots, then presents deterministic bounded Rust findings through an accessible modeless dialog. It is runtime-free and read-only: no auto-fix, materialization, canvas navigation, or selection mutation. `document.molecule.smarts.query.v1` searches only the accepted current document's direct molecules through bounded raw or selected-root input; the Qt dock reveals a result only through a Rust-held one-use receipt and finite identity-free paint bounds. Patch 3 automated acceptance covers the canonical Rust gate, sealed build, public Rustdoc/Python isolation oracle, packaged CLI, installed PyO3 receipt lifecycle/module isolation, and offscreen Qt lifecycle. Private SMARTS helper/capability PyClasses are unregistered; only durable closed error enums retain `V1`. Real-window/human visual, CI, and release acceptance remain open. Compact sugar notation, sugar-name inference, known-group expansion, oxidation inference, generated names, broad historical search, and directory/file/database discovery remain preproduction drops or future contracts; their retired catalog/code families are not restored. |
| FQ-011 | Geometry repair and bounded rotation | Supported in bounded Rust operations. | Clean Geometry plus Snap to Hex Grid, Straighten Terminal Bonds, Normalize Bond Lengths, Normalize Bond Angles, and Normalize Ring Geometry commit native plans atomically. The separately owned Rotate Selected Atoms route is also native. Fused or multicycle normalization, heuristic cleanup, bond edits, stereochemical inference, transform stacks, historical Rotate mode, and unported gestures are preproduction drops. |
| FQ-012 | Haworth insertion | Supported: Rust recipe/candidate/session/render ownership with a native Qt chooser. | The product inserts the four explicit alpha/beta D-glucopyranose and D-glucofuranose recipes at a shared snapped anchor. Broader carbohydrate inference, attachment, and preferences are future contracts. |
| FQ-013 | Direct glycosidic Haworth insertion | Supported in its closed structural slice: Rust composition and native Qt dialog. | It accepts only the documented neutral two-ring, one-exterior-oxygen topology and preserves state on invalid, stale, occupied, cancelled, or closed deliveries. Named-sugar, anomer, linkage, D/L, and stereochemical inference are future contracts. |
| FQ-014 | Native peptide insertion | Supported only for the strict typed native-17 profile through the Qt-native/PyO3 bridge. | `Import Supported Peptide Sequence...` constructs a typed Ferrum peptide structure plan directly; domain owns peptide semantics, document prepares the typed graph as a molecule, and chemistry owns layout. `prepare_ferrum_peptide_insertion_v1` is the only public bridge. It neither compiles nor parses legacy template SMILES, creates no CLI or protocol operation, and refuses unsupported residues through typed native errors. Catalogs, broader authoring, termini UI, and structure/mass/pI claims remain preproduction drops. |
| FQ-015 | PubChem lookup and insertion | Preproduction drop. | The product has no live network lookup route or fallback. A future service integration needs its own reliability, identity, and failure contract. |
| FQ-016 | User templates | Supported: Rust template admission/insertion with a native Qt catalog client. | Ferrum-owned user templates support bounded save, inspect, refresh, and placement with fresh identities and safe catalog confinement. System-template compatibility is not implied. |
| FQ-017 | Presentation objects and drawing defaults | Supported in bounded Rust-rendered slices. | Supported text, plus, normal arrow, `CurvedElectronArrowV1`, `CurvedRetroArrowV1`, `CurvedNormalReactionArrowV1`, `CurvedEquilibriumArrowV1`, wavy, bracket, geometric, vector, paper, drawing-default, Polyline, and Polygon operations retain native facts, history, and rendering. Polyline/Polygon use the accepted opaque Rust-owned incremental transaction; accepted vertices are durable, optional hover is display-only, Rust issues the overlay appearance, and the full-vector bridge is retired. Qt supplies scene conversion and events, with a transient accepted-press coordinate used only to de-duplicate real/QTest double-click delivery. Curved-arrow creation uses FQ-007's opaque Rust gesture contracts rather than frontend-authored persistent geometry. Each curved-arrow action captures three points, paints only its Rust projection, and commits only a prepared native receipt. The closed ownership contract is in [CDML_BACKEND_TO_FRONTEND_CONTRACT.md](../../CDML_BACKEND_TO_FRONTEND_CONTRACT.md) and the accepted bounded plan is in [FULL_PARITY_RUST_FIRST.md](../active/FULL_PARITY_RUST_FIRST.md). Unsupported faces and unaccepted editing variants remain future contracts. |
| FQ-017a | Atom numbering and marks | Supported: Rust document/render ownership with native action clients. | Number visibility and the accepted chemical-mark toggles persist through history and save/reopen. New mark families or selection semantics require a future contract. |
| FQ-018 | Object transforms and ordering | Supported in bounded Rust operations. | Direct-root scale, mirrors, ordering, alignment, generated linear form, and complete-root translation retain native validation, history, and refusal behavior. Broader transform semantics remain future work. |
| FQ-019 | Clipboard and selected SVG | Supported: Rust fragment/session/render ownership with native Qt MIME clients. | Copy, Cut, Paste, and selected SVG use closed fragment/root grammars, authenticated provenance, fresh identities, and mutation-safe failure handling. New public clipboard or artifact APIs are future contracts. |
| FQ-020 | View and personal UI state | Supported: ordinary Qt view clients over native document/render state. | Bounded zoom, page/content framing, grid visibility/snap, tab view state, theme, toolbars, Next Drawing, properties observation, preferences, and workspace state remain application state rather than CDML or Rust document state. Broad historical mode/view configuration is a preproduction drop. |
| FQ-021 | Product metadata and help | Supported: Ferrum Qt release boundary. | About, CLI, version lookup, product naming, licensing, and lineage acknowledgement are Ferrum-owned. Historical backend branding is provenance, not a runtime claim. |
| FQ-022 | Built-in action registration and plugins | Supported for explicit built-ins; third-party execution is a preproduction drop. | The ordinary menus register shipped native actions. An extension system must begin with a new discovery, permissions, lifecycle, compatibility, and failure-containment design. |
| FQ-023 | Compatibility bridge workers | Preproduction drop. | The OASA bridge worker family was retired with the compatibility host. Native asynchronous work remains only where a current native workflow needs it; a replacement bridge is not planned. |

## Evidence and follow-up

The M15 utility-disposition closure records the retained strict peptide,
linear-form, geometry-repair, and rotation routes while retiring unowned compact
sugar, catalog, group, and search families. The M16 host-retirement closure
establishes a single ordinary native desktop route, a production package with no
OASA dependency, and disposable local-program evidence. The delivered CDXML profile has
separate success and refusal/nonmutation evidence.
Earlier migration reports that describe a compatibility host, OASA routes, or
their test suite are historical provenance and do not describe current behavior.

### M19 supported-row evidence index

M19 is accepted and complete as the bounded capability-matrix closure. This index links each
supported row to already accepted evidence, rather than prescribing a new test matrix or claiming
complete OASA/BKChem parity. The
[current migration handoff](../reports/current_migration_handoff_20260814.md) links the accepted
slice receipts; its named compact semantic tests are durable only where they protect a bounded
behavior. Local-launcher, walkthrough, visual, package, and thread observations remain one-time
acceptance evidence.

| Supported rows | Existing accepted evidence | Validation lane |
| --- | --- | --- |
| FQ-001 | Native Open, current-tab replacement, Recent, and host-retirement receipts. | Compact native lifecycle semantics; ordinary local-launcher walkthrough. |
| FQ-002 and FQ-003 | Local CDML and decoded CD-SVG admission, provenance, save/reopen, and projection receipts. | Rust/binding/native admission semantics; one-time staged-runtime and public Open evidence. |
| FQ-002a | CDXML Wavy/Bold/Dash decoder, document lowering, native renderer, and File/Open receipts. `tests/e2e/e2e_cdxml_open_qt.py` opens one styled CDXML via the visible Qt action, requires exactly one issue-free render plan, proves the projected Wavy/Bold/Dashed presentations and persisted `s1`/`b1`/`d1`, then proves the Current Tab route refuses without mutation. The registered `tests/e2e/run_all.sh` route executes that check against the staged runtime. | Deterministic Rust/document/render/PyO3 behavior plus offscreen Qt File/Open E2E. This is automated implementation evidence, not real-window visual acceptance. |
| FQ-004, FQ-008, and FQ-009 | Native chemistry-import/export and coordinate-preparation receipts. | Rust/document and focused native behavior semantics; accepted worker walkthroughs where applicable. |
| FQ-005 and FQ-006 | Native one-record and selected multi-record SDF receipts and CLI atomic-publication coverage. | Rust/document/binding export semantics and bounded local CLI behavior; Qt publishes only a fresh complete native receipt, while staged-runtime window evidence remains one-time. |
| FQ-007, FQ-007a, FQ-007b, and FQ-007c | Native atom, bond, ring, path, property, gesture, history, and render receipts. Regular-ring permanent coverage proves C3-C8 action handoff and durable topology, Escape no-mutation/disarm, occupied no-mutation with an armed retry, and accepted-mutation failed-refresh retirement. One-time real-Qt evidence demonstrated ring save/reopen and Undo/Redo; the generic persistent-document and history contracts cover those shared behaviors permanently. `HistoryCapacity` was removed as an unreachable commit refusal while preparation retains typed history-resource exhaustion. `Change Element` closure: `/private/tmp/ferrum-change-element-projection-boundary-fix.md`, prior local-runtime offscreen visual E2E, fresh local-runtime fail-once regression, and `/private/tmp/ferrum-change-element-final-acceptance-review.md`. Direct normal-bond evidence covers every normal order across `ExistingExisting`, `ExistingNew`, `NewExisting`, and `NewNew`, including blank-canvas persistence, one atomic history transition, Undo/Redo, and mutation-free Escape. Directed-wedge evidence covers both `w1` and `h1` across the same four forms, preserved tip-to-base CDML order, immutable admission-to-commit render operations, history, save/reopen, and nonmutating cancellation/refusal. Polyline/Polygon evidence covers ordered-path cardinality and geometry refusal, durable accepted vertices, display-only optional hover, Rust-issued overlay appearance, renderer preparation, opaque receipt consumption, one history transition, cancellation, snapshot-based projection recovery, and the transient Qt double-click de-duplication coordinate. The focused public binding and Qt behavior receipt passed 26 checks. A fresh local build and full `./all_test.sh` receipt passed 7,548 hygiene checks, local CLI smoke and listed local CLI/Qt E2Es, 279 staged Python binding checks, and 214 Qt checks with one skip. M3.P3 Retro and M3.P4 normal reaction add accepted terminal-arrow evidence for the shared three-point lifecycle, native projection, receipt fencing, commit, cancellation, refusal, history, and save/reopen. M3.P5 adds independently lowered lanes and opposing heads to that evidence; its closed contract is in [CDML_BACKEND_TO_FRONTEND_CONTRACT.md](../../CDML_BACKEND_TO_FRONTEND_CONTRACT.md). | Compact Rust/PyO3/native behavior semantics; isolated QAction/viewport proofs are one-time local-runtime evidence with exact provenance and no manual gate. |
| FQ-010 and FQ-011 | Bond-capacity, linear-form, geometry-repair, rotation, and bounded current-document SMARTS receipts. | Compact semantic behavior; M4b Patch 3 has automated Rust/build/public-surface/packaged-CLI/installed-PyO3/offscreen-Qt evidence. Real-window/human, CI, and release acceptance remain separate. |
| FQ-012 and FQ-013 | Haworth and direct-glycosidic insertion receipts. | Recipe/transaction/render/native-action semantics; local-launcher chooser walkthroughs are one-time evidence. |
| FQ-014 | Typed native-17 peptide insertion closure. | Bounded domain-plan, document-preparation, chemistry-layout, and Qt/PyO3 bridge semantics. |
| FQ-016 | Ferrum-owned user-template receipts. | Admission/insertion/catalog behavior semantics; public walkthrough is one-time evidence. |
| FQ-017 and FQ-017a | Presentation, drawing defaults, atom-number, and mark receipts. | Focused document/render/native-action semantics. |
| FQ-018 | Direct-root transform, ordering, alignment, and translation receipts. | Rust/session semantic behavior. |
| FQ-019 | Clipboard and selected-SVG fragment receipts. | Fragment/provenance/session semantics; worker and UI observations are one-time evidence. |
| FQ-020 and FQ-021 | Qt view, preferences, metadata, help, and release-boundary receipts. | Focused native behavior and ordinary launch evidence. |
| FQ-022 | Explicit built-in registration and no third-party extension contract. | Supported built-in behavior evidence; extension execution is a recorded pre-production drop. |

FQ-002a records the bounded CDXML new-document profile and its success/refusal evidence;
FQ-002b retains the remaining local-format refusals. FQ-015 and FQ-023 are pre-production drops;
no parity test is owed.
Future-contract exclusions in supported rows remain outside their named lane until a later plan
adopts them.

### CDXML presentation acceptance boundary

The supported CDXML depiction slice is deliberately narrow: only direction-free
single `Display="Wavy"`, `Display="Bold"`, and `Display="Dash"` bonds enter the
single persistent presentation model and native renderer. The Qt chooser mirrors
that closed model with Normal, Wedge, Hashed wedge, Haworth front edge, Bold,
Dashed, and Wavy; it does not preserve historical Adder or Dotted authoring.
Read-only source inspection may report unsupported legacy facts, but cannot turn
them into authorable records.

Automated source, Rust, staged-runtime, and offscreen Qt receipts establish this
bounded behavior. They do not establish full BKChem/OASA parity, a real-window
human visual judgment of the new line depictions, CI execution, package/release
sign-off, or a broader ChemDraw presentation grammar; those remain separate
acceptance work or future contracts.

Future work must start from a named user workflow and an explicit owner. It may
promote a future-contract row or replace a preproduction drop, but it must not
reintroduce a compatibility host or treat the legacy catalog as a required
parity inventory. The active plan remains the detailed slice record:
[ferrum-plan-v3.md](../ferrum-plan-v3.md).

## Historical provenance

Before the 2026-08-15 retirement, this file catalogued a migration-era
compatibility host and OASA-backed routes. Those descriptions explain the
origin of the FQ identifiers only. They are intentionally not current owners,
runtime dependencies, test requirements, or future commitments.