docs(rcp): publish RCP v1.0.0 spec + stability policy (#35)

[Narrator]

Closes #35.

Summary

Lands the public Runtime Context Protocol (RCP) v1.0.0 spec at docs/rcp/v1.md, plus the two decision records that back it (RFC 0001 — package extraction, RFC 0002 — v1 ratification). Together these are the artifact IDE-vendor outreach points at: an explicit, falsifiable stability policy with a schema-level differentiation lever versus runtime-only MCPs.

This PR ships the spec only. Tool-name canonicalization (#33), @domscribe/protocol package extraction (#32), telemetry (#34), SourcePosition schema enforcement (#38), and npm publish (#39) land in their own PRs this sprint.

What's in the spec

• §0 Design intent — RCP framed as the build-time, framework-aware complement to WebMCP and Chrome DevTools MCP, not a competitor at the same layer. The framing is in the spec itself (not just the release post) because vendors read the spec, not the post.
• §3 Tools, §4 Prompts — canonical snake_case names per RFC 0002. Dotted aliases through v1.x per §7.4.
• §5 Wire schemas — ManifestEntry, RuntimeContext, Annotation, ProblemDetails, and now §5.5 SourcePosition as the v1 stability anchor.
• §6 Error codes — full DomscribeErrorCode vocabulary (22 codes).
• §7 Stability policy — frozen / additive / breaking rules with two new SourcePosition-specific falsifiability rows in §7.6.
• §8 — exact @domscribe/protocol package surface (the six-export contract from RFC 0002).
• §9 References — both RFCs linked.

RFC 0002 deltas in this PR

The prior spec draft (commit b4d99c0 by staff-swe-5) predated RFC 0002. This PR's spec commit (6e5e0b6) folds in the four RFC 0002 decisions:

1. SourcePosition required on every resolve_* / query_* output — encoded as a schema-level invariant, not a relay convention. New §1 MUST clause, new §5.5, new §7.1 freeze entry, two new §7.6 examples. This is the load-bearing differentiator vs runtime-only MCPs.
2. snake_case canonical tool grammar — already in the prior draft; preserved.
3. Six-export @domscribe/protocol package surface — new §8 enumerates exactly what the package exports so consumers know what they can import without grepping the npm package.
4. Build-time complement framing — new "Design intent" subsection. Honors DOP-memo language without being defensive.

RFC 0001 status moves from Proposed to Accepted (ratified by RFC 0002, sprint 2491) in this PR.

Why RFC 0002 is committed in this PR

Same rationale staff-swe-8 used for RFC 0001 in commit 836f7fa: the spec cross-links to ../rfcs/0002-protocol-v1-execution.md. If RFC 0002 isn't in the branch, the link renders broken on GitHub, failing the "renders cleanly" acceptance criterion. Verbatim PE content, no edits.

Acceptance criteria coverage

• docs/rcp/v1.md renders cleanly on GitHub — all cross-links resolved within the branch (both RFCs present).
• Stability policy explicit and falsifiable — §7.1–§7.6 with 11 worked examples; a reader can predict the verdict on a candidate change without consulting maintainers.
• SourcePosition explicitly named as a v1 stable contract — §5.5 (dedicated section), §1 (MUST clause for servers), §7.1 (freeze list, separate entry).
• Linked from README + TECHNICAL_SPEC.md — already in commit b4d99c0; verified resolved in this PR.
• RFC 0001 status moved from Proposed to Accepted — commit 6e5e0b6.

What was tested

The acceptance criteria are documentation-shaped, not code-shaped — there are no tests to run. Verification was:

• All four markdown cross-link targets (../rfcs/0001…md, ../rfcs/0002…md, README→docs/rcp/v1.md, TECHNICAL_SPEC→docs/rcp/v1.md) exist in the branch.
• Numbered section references (§3, §5.5, §6, §7.1, §7.6) all resolve within v1.md.
• The package surface table in §8 matches the RFC 0002 enumeration verbatim.

What was NOT tested and why

• @domscribe/protocol does not yet exist on npm — §8 documents the contract for the package that Extract @domscribe/protocol package (RCP versioning unit) #32 extracts and Publish @domscribe/protocol@1.0.0 to npm + verify non-author install #39 publishes. The spec being slightly ahead of the package is intentional; both must land together by sprint close.
• SourcePosition is not yet enforced at the schema level — that is Make SourcePosition required on every resolve_*/query_* output schema #38. The spec calling it required ahead of the schema enforcement is intentional sequencing per the PM plan; if Make SourcePosition required on every resolve_*/query_* output schema #38 slips, the spec text is the source of truth the schema must align to.
• I did not run pnpm build or pnpm test. This PR touches docs/** and *.md files only — no source code paths.

Commits

1. 836f7fa (existing, staff-swe-8) — commits RFC 0001 referenced by the spec.
2. b4d99c0 (existing, staff-swe-5) — initial v1.0.0 spec + README/TECHNICAL_SPEC cross-links.
3. b9873cc — commits RFC 0002 referenced by the updated spec.
4. 6e5e0b6 — aligns v1 spec with RFC 0002: SourcePosition anchor (§1, §5.5, §7.1, §7.6); package surface (§8); RFC 0001 status to Accepted.

Out of scope (deferred to other PRs this sprint)

Concern	PR
@domscribe/protocol package extraction	#32
snake_case tool registration + dotted aliases at MCP SDK layer	#33
Telemetry endpoint (Cloudflare Worker + KV) + relay client	#34
SourcePosition schema-level enforcement (Zod)	#38
npm publish + non-author install verification	#39