feat: ship reversible identity v2 migration

[treylom]

Summary

• make one canonical AGENTS.md the new-install identity surface, including the SOUL v2 schema slots
• add rules/orchestration.md §11 (R1–R5) and route it from rules/INDEX.md
• add an explicit migrate-identity preview/apply/rollback path for existing AGENTS.md and legacy SOUL.md installs
• align English/Korean setup guidance, packaged skills, config fallback, and bridge documentation with the one-file contract

Migration safety

• preview is the default
• the active identity file is never overwritten
• apply creates a type-correct backup, AGENTS.md.v2 candidate, and SHA-bound receipt
• rollback removes only an unchanged receipt-bound candidate; changed candidates fail closed
• SOUL-only workspaces remain active on SOUL.md until an operator-reviewed cutover

Verification

• npm test — 252/252 pass
• focused identity contract suite — 62/62; Korean safety regression — 13/13
• Windows protocol regression — 15/15; evidence/CLI/hook suite — 38/38
• isolated init --non-interactive / doctor --non-interactive / clean-diff smoke — pass
• npm pack --dry-run --json — pass, 300 packaged files
• independent transfer check with a different SHA implementation — 2/2 byte-identical
• secret scan with positive bait — bait detected, proposed diff 0 hits; added absolute home paths 0
• git diff --check — pass
• GitHub Actions: push run 31942280953 and PR run 31942283143, Ubuntu/macOS/Windows 6/6 pass

Windows CI remediation

The first PR run exposed failures already present on base master (baseline run 31664945809): a POSIX-only mode-bit assertion, locale-dependent JSON I/O, and an unnecessary rewrite of an already-active matching flow that could race on Windows rename semantics. Commits 7322b30, e937601, and a37e1a4 preserve the POSIX contract off Windows, enforce UTF-8 input plus ASCII-safe JSON output, add Korean cp1252 regression coverage, and make matching-flow start read-only/idempotent while retaining new-flow writes and different-flow denial.

Independent review

• reviewer: 글재경
• content review: RED on one Korean safety-information asymmetry; fixed in 3d2c6e4
• content re-review GREEN
• Windows protocol review GREEN
• final concurrency review GREEN
• durable evidence: AI_Second_Brain/100-project/2026-08-16-bot-rules-docs-redesign/30-execution-log.md

Coordinates

• base: e9e37e39e478c00250e95b4f63b8eb8cb10c1f66
• head: a37e1a46a5cd74c915cd2b7152438d29e65f9286
• full binary diff SHA-256: c58338961e17e0bcecca67ffdec3c47d8e35853c7dcc7e1b3ec334e86bdac921

Draft only. Do not merge until the BRD final review and operator decision.