feat(mcp): reconcile sources and refresh session tools

[JAORMX]

Stage

Implementation — stacked on #1527

Contract and baseline

• Plan / Interface PR: docs: plan MCP source reconciliation #1527
• Exact amended plan baseline: 316f99d100298f7da57966de25c322baac0a8661
• Includes main through 6c75a42d9cad502685a42f5418f2bc99b9ae6376 without rewriting integrated history.
• The directing human explicitly authorizes implementation before plan merge. This PR targets plan/mcp-source-reconciliation; humans merge the plan first, then retarget/review this PR for main.
• Interfaces match the explicitly authorized amended contract: Yes. The plan is still unmerged; no merged approval is claimed.

Summary

• Automatically reconcile ToolHive workloads and MCP tool/resource/prompt notifications through one bounded, coalesced source reconciler.
• Publish complete immutable direct-MCP runtimes; keep active runs and resource/prompt operations pinned until settlement, with bounded retirement and revision-based engine rebuilding.
• Preserve existing exact-name authority. Removed names become unavailable; previously granted same names can reappear. New names require explicit owner refresh.
• Add Session.GrantToolAuthority, direct refresh gRPC/HTTP controls, cached revision/status, SDK support, and unified mecatui /mcp-refresh routing.
• Keep broker consent/cancellation and direct refresh separate; retain /tools-connect as a broker-only compatibility alias.
• No durable capability digests, revoked records, snapshot migration, or new endpoint-credential policy.

Acceptance coverage

All 12 amended ACs are implemented and traced:

• AC1.1–1.3: ordered sources, LKG/empty handling, real notifications/polling, input bounds, no automatic consent, shutdown.
• AC2.1–2.3: all-or-nothing publication, production engine variants, runtime consistency across prompt/retry/restored approval/delegation/direct teams and resource/prompt operations.
• AC3.1–3.3: removed/reappearing names, state-preserving authority union, delegation/resume name semantics.
• AC4.1–4.3: owner/lifecycle/mutation/ambiguous-save/cancellation matrices, pinned response revisions, gRPC/HTTP/TUI parity and broker isolation.

The plan's landed status in this diff is a proposed transition, effective only when the implementation merges.

Verification

Passed on final candidate:

• task generate
• task lint
• task test (race and module/standalone gates)
• task api:check
• task sdk:api:check, task sdk:test (276 tests), task sdk:build
• task docs, task site:build
• task ac-trace-strict
• go run ./cmd/mecademo

Optional Bun-only e2e was not rerun locally because Bun is unavailable; required SDK gates pass.

Final panel:

PANEL: ship_blockers=0 important=1 advisory=2 reviewer_failures=0

Non-blocking suggestions retained as optional follow-ups: consolidate candidate pagination if the abstraction proves worthwhile; use typed sorting and non-cryptographic polling jitter. No technical contract deviations.

Two pre-existing strict-trace references were corrected to the actual current provider/SDK proof names without changing tested behavior. Generated protobuf/API output accounts for a substantial portion of the diff. The discarded broader implementation is preserved separately and is not part of this stack.

Tracking: #1511