[v0.2] Replace internal phase labels with versioned capability terminology

[Teakowa]

Closes #140 (implementation lane; QA/merge decisions remain).

Sweep scope

Removed internal phase-number planning labels (M4–M14, "milestone M…") from active/living material where they served as the roadmap model. Historical record (git history, closed PR/issue threads, commit-subject quotes, archival scripts/fixtures) is untouched.

What was replaced, where

• Crates (40 files, commit d30736c): code/doc comments in all crates/* — phase labels replaced with the concrete issue references (e.g. #97, #98, #117, #128–#131) or capability names they pointed at ("safe-edit transaction contract", "wright-bench harness", "OPY support matrix", "declared P0 surface"). No code symbols, APIs, identifiers, or test behavior changed; only prose/comments.
• Docs + README + CONTRIBUTING (8 files, commit f9432e7):
  • docs/ostw/compatibility-baseline.md — "M13 Investigation" reframed as the OSTW reference/corpus/support investigation ([M13 investigation] Establish OSTW reference, corpus, licensing, and semantic support baseline #113); section headers and "post-M13 reassessment" → roadmap reassessment; decomposition A–E phase identifiers kept (defined in the same doc).
  • docs/embedding.md, docs/language-services.md — M14 → issue refs ([M14 foundation] Make source-edit transactions project- and frontend-aware #128–[M14 language services] Converge LSP rename on the shared semantic refactoring contract #131).
  • docs/compatibility.md, docs/compatibility/upstream-references.md — "M13 investigation" → "OSTW reference investigation ([M13 investigation] Establish OSTW reference, corpus, licensing, and semantic support baseline #113)"; "M11 evidence set" → "OverPy compatibility evidence set".
  • docs/specs/SPEC-99-stability-rules.md — doc-owned M12 labels removed; verbatim commit-subject quotes ((M12) at c5b46f3/a54433b) kept as historical record.
  • README.md — M13 status/foundation labels → capability language ("native OSTW frontend", "native frontend & HIR lowering baseline").
  • CONTRIBUTING.md — one convention bullet: new issues/PRs/living docs use capability/issue/version terminology, Roadmap to v1.0: stable Workshop tooling platform #134 is the normative roadmap.
• Open issues/PRs: audited all open issues (Roadmap to v1.0: stable Workshop tooling platform #134, [v0.2] Establish the language-provider boundary and canonical Workshop core #135, [v0.2] Rebaseline language ownership and licensing boundaries #136, [v0.2] Route source mutation semantics through providers #139, [v0.2] Replace internal phase labels with versioned capability terminology #140, [v0.2] Add LPP client, provider discovery, and process lifecycle #142, [v0.2] Cut Wright over to workshop-rs #143) and PRs (chore(deps): bump sha2 from 0.10.9 to 0.11.0 #95, [v0.2] Rebaseline language ownership and licensing boundaries #144) — none use phase numbers as the roadmap model; no body edits were needed. Roadmap to v1.0: stable Workshop tooling platform #134 already records the planning convention.
• PR M14: validated source editing across Wright frontends (autonomous checkpoint) #133 audit: the merge landed M14 terminology in crates/wright-driver|language|lsp|ostw|consumer, docs/embedding.md, docs/language-services.md, tests/; all occurrences were replaced above as normal follow-up. Historical PR/commit record untouched.

Exclusions (owned by #136 / PR #144 — NOT touched, left as follow-up)

• docs/adr/*, docs/architecture.md (contains "M13" references), docs/licensing.md, docs/README.md (M10/M11/M13 references) — per lane boundary.
• Also out of enumerated scope, noted for follow-up: crates/wright-workshop/src/catalog/data/catalog.json ("M5 support matrix" provenance strings in catalog data), scripts/m11-inventory.py/scripts/acquire-corpus.py/compatibility/README.md/adapter/test/adapter.test.js (historical acquisition-tooling and fixture provenance).

Acceptance criteria mapping

• Living code/docs and active release-facing work no longer use internal phase numbers as the roadmap model — sweep verified by rg '\bM[0-9]+\b' over crates/ and non-excluded docs/ (only historical commit quotes and out-of-lane files remain). ✓
• Roadmap to v1.0: stable Workshop tooling platform #134 is the normative pre-1.0 roadmap — already referenced in AGENTS.md; convention bullet added in CONTRIBUTING.md. ✓
• Closed historical work remains intact — no history rewriting; commit-subject quotes preserved. ✓
• New planning work uses feature names/versions — convention recorded in Roadmap to v1.0: stable Workshop tooling platform #134 and CONTRIBUTING.md. ✓

Validation

• cargo fmt --check — pass
• cargo clippy --workspace --all-targets -- -D warnings — pass
• cargo test --workspace --all-targets — pass (55 test binaries, 0 failures)
• git diff --check — pass