MCP 2.5.2 — compact carryover tool responses

Small patch finishing the response-budget work from 2.5.1: the carryover pair was the last tool surface still returning fat responses.

Changed

• memory_carryover_plan / memory_carryover_apply responses compacted (#52): measured live at 3,915 / 7,745 tokens for a 28-file carryover — the apply response contained every candidate record twice, and each record repeated derivable onboarding paths plus an identical per-path reason. Both tools now file the full records under temp/tool-reports/memory_carryover_*/ (keep-last-5 / 7-day retention, secret-redacted) and return per-decision source_path digests (capped at 25 per group with an overflow marker), carriedPaths on apply, and an inline reportPath. Commits, intent note, and counts stay inline. Backward-compatible: the slimmed arrays are flexible envelope detail, same semver posture as 2.5.1.

Known issues under investigation from this release cycle: #53 (worktree_start provider setup is silent for minutes — async visibility planned) and #54 (worktree_start can branch from stale local bases; also silently converts the fast index-copy seed into a full reindex).

Full changes: #55