fix(mcp): harden connection recovery

[mattzcarey]

Summary

Harden three supported MCP connection-recovery paths:

• apply persisted retry budgets when connectToServer() reports { state: "failed" } instead of throwing;
• finish in-flight restore/discovery work before migrating an auto-generated server id to a caller-supplied stable id;
• close a connection replaced through the legacy connect() path and clear its terminated persisted session id.

Why this is needed

tryN() only retries thrown errors, while MCP connection failures normally resolve as a failed result. Documented retry options therefore stopped after one attempt. Stable-id migration could also rename a connection while restore still addressed the old id, orphaning discovery. Finally, the internally-used legacy reconnect path dropped replaced transports without closing them.

The minimized regression tests still fail on current main for all three symptoms and pass with this branch.

Validation

• pnpm --filter agents exec vitest run src/tests/mcp — 30 files, 553 tests passed
• focused package lint and both Agents TypeScript projects passed
• build, exports, formatting, and repo lint passed
• repo-wide typecheck remains blocked by unchanged main voice errors in examples/voice-agent and voice-providers/assemblyai

Includes a patch changeset for agents.

[changeset-bot]

🦋 Changeset detected

Latest commit: 94d0911

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
agents	Patch

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[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no bugs or issues to report.

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commit: 94d0911