Keep activated tools advertised across resume and rebuild - #912

Summary

• Persists tool_search-activated tool names in run.json and re-activates them before the first post-resume inference, so the wire matches the transcript after restarts and rebuilds
• Names the activated set in the compaction handoff so the folded summary and the advertised wire agree
• Refuses registered-but-unadvertised tool calls with an error pointing at tool_search, instead of silently dispatching (submit_output and Codex-native shell/update_plan proxies are exempt)
• Adds per-project pinnedTools in .corbits/settings.json for MCP tools that should always be advertised without activation
• Fixes corbits resume <id> dropping turnsUsed/mcpServers/startedAt by loading run.json in prepareTUISession

Verification

• bun run lint, bun run typecheck, and bun run build pass
• Touched test files pass (183 tests, 0 failures); the full suite's remaining failures are pre-existing sandbox-environment issues (git worktree, home-dir, and subprocess tests fail identically on main)
• Resume seed carries activatedTools, run.json round-trips the field, and the dispatch gate errors toward tool_search then admits the call after activation

Fixes CL-7680