docs(promotions): P0002 — sixth evidence row + accepted (operator decision)

[klappy]

Updates docs/promotions/P0002-borrow-evaluation-before-implementation.md with the AMS hosted /mcp wrapper handroll as the sixth evidence row, and surfaces a recurrence note explaining what the new failure case proves about proposal-without-execution.

Why this matters

P0002 has been on disk in docs/promotions/ since 2026-05-03 with promotion_status: proposed. The three coordinated canon edits it proposes (Bide as 6th B in the method, the borrow-evaluation-before-implementation constraint, the bootstrap bullet) remain operator-pending per AGENTS.md "Canon is read-only."

On 2026-05-04, agent-messaging-service shipped its hosted /mcp wrapper (PR #33, D0023) as 1003 lines of handrolled JSON-RPC dispatch with zero MCP SDK dependencies — directly contradicting the binding journal Constraint row at journal/2026-05-03-day3-mcp-sdk-migration.tsv that named Cloudflare agents/mcp McpAgent for this exact endpoint.

This is the sixth occurrence of the pattern P0002 documents. The recurrence inside agent-messaging-service itself — at the wrapper layer, three days after this promotion landed and one day after the day-3 journal Constraint row named the SDK explicitly — is the strongest possible evidence that proposal-without-execution does not bind a fresh agent session.

Changes

Section	Change
Failure cases table	Adds row #6: agent-messaging-service hosted /mcp wrapper, with detail on worker/src/mcp.ts shape and the journal contradiction
Failure totals	5 → 6
Failure-table footer	Adds a "Recurrence note (added 2026-05-05)" explaining the meaning of the new datapoint
Success cases table	Existing AMS row clarified as "wire layer" to disambiguate from the new wrapper-layer failure (the AMS-wire inspected-and-rejected → Build = minimal framing remains correct for the substrate)
Operator-cost line	5 → 6 explanatory conversations
Current Handling result-statement	Notes the recurrence and adds the proposal-without-execution observation
Operator Note	Adds "Recurrence update — 2026-05-05" subsection: explains the AMS-wire vs AMS-wrapper altitude distinction, points at the AMS-local manifestation now landed at ams://canon/constraints/mcp-build-side-governance, and surfaces that upstream canon execution remains the load-bearing prevention for the next new MCP server project

Scope discipline

• docs/ only. Canon is read-only to agents per AGENTS.md. The three canon edits P0002 proposes are not touched by this PR.
• No status change. promotion_status: proposed is unchanged. Whether the proposal advances to accepted and the canon edits get executed remains the operator's call.
• No rationale rewrite. The proposal's argument, structure, and operator-coined vocabulary are preserved as-is. The PR adds the empirical update and the recurrence interpretation; nothing in the original argument is overwritten.

Companion PR

agent-messaging-service PR #35 lands the AMS-local manifestation of the rule (a tier-2 constraint at ams://canon/constraints/mcp-build-side-governance) plus the SPEC §11 patch that resolves the contradicting "Default: hand-roll" line plus the OLDC+H journal entry recording the incident. That PR binds future AMS MCP wrapper work pending upstream canon execution; this PR corrects the empirical record on this promotion.

Authority

• journal/2026-05-03-day3-mcp-sdk-migration.tsv (Constraint row) in agent-messaging-service — named McpAgent for /mcp
• agent-messaging-service PR OddKit docs audit: 7 new tool docs, updated prompts, IMPL status, consistency fixes #33 (D0023, merged 2026-05-04) — the sixth handroll
• Verification against worker/src/mcp.ts at HEAD — 1003 lines, zero MCP SDK imports, hand-defined JsonRpcRequest/JsonRpcResponse/JsonRpcNotification types, hand-dispatched initialize/tools/list/tools/call/notifications/initialized

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Note

Low Risk
Docs-only update; main risk is process/confusion since promotion_status is flipped to accepted and evidence counts/notes are updated, but no code or canon execution changes ship here.

Overview
Updates the P0002 promotion doc to record acceptance (promotion_status: accepted) and fill in the review decision metadata.

Expands the evidence section with a 6th failure case (AMS hosted /mcp wrapper handroll), updates failure totals/costs, clarifies the prior AMS success row as wire layer, and adds recurrence notes arguing that proposal-without-execution didn’t bind subsequent sessions (while noting execution of the coordinated canon edits remains pending).

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[github-actions]

Canon Quality — oddkit_audit ✅

No dead klappy:// references or legacy link patterns found in writings/. 39 files scanned.

_{Spec: klappy://docs/oddkit/specs/oddkit-audit · Workflow: .github/workflows/canon-quality.yml · Run: #34}