fix(mcp): harden unindexed rename recovery

[zzet]

Summary

• route unindexed rename recovery through the repository indexer that owns the target file
• restore the current bounded extraction path with raw/native admission and coordinate-stable preprocessing
• refuse arbitrary command transforms when a declaration-only raw edit cannot be proven safe
• cover multi-repo ownership, repo-specific file limits, transform refusal, BOM coordinates, and admission cancellation

Validation

• go test -race ./internal/indexer ./internal/mcp
• go vet ./internal/indexer ./internal/mcp
• git diff --check
• go test ./... (all packages passed except the existing cmd/gortex post-test real-user-state guard, which observed a write to ~/.gortex/cache/query-log.jsonl after that package itself printed PASS)

Follow-up to #574.