fix(clients): a preview app no longer knocks the desktop's own server offline

[t3dotgg]

After I updated to the latest nightly, the desktop app said "Mainbook is offline" about its own local server. Reconnect did nothing. The local server was healthy.

The cause: T3 Code (Alpha), the Orchestrator v2 preview, was running on the same Mac from the same ~/.t3 home. So it had the same environment id and label, but it uses orchestration protocol 2. Relay discovery reported the Alpha server's descriptor for that id. watchDiscoveredCompatibility then marked nightly's local primary environment "unsupported", switched it off, and dropped its socket. The traces show setCompatibility calling disconnect on the primary 3 seconds after launch.

Relay discovery describes the server behind the relay route. Now it sets compatibility only on relay targets. Direct connections (the desktop's own server, saved URLs, SSH) already check the protocol in their socket handshake.

Proof: a new registry test puts an incompatible discovered descriptor on a connected primary and on a relay target. Without the fix, the primary gets disabled, the same as the live failure. With the fix, only the relay target is disabled and the primary stays connected. The client-runtime suite (1671 tests), typecheck, lint, and fmt pass. I found the root cause from live traces and by comparing the /.well-known/t3/environment output on both local servers.

Created with Claude Opus 5.5 in Claude Code.

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes
  • Compatibility checks for discovered environments now apply only to relay targets. When an unsupported relay shares an environment ID with a connected primary target, only the relay entry is disabled; the primary remains connected and enabled. Non-relay targets are not affected by discovered relay compatibility results.

[github-actions]

Thread transfer impact

✅ Thread transfer remains within every enforced ceiling.

Provider	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	Total thread wire	13.5 KiB	13.5 KiB	+42 B (+0.3%)	15.1 KiB	✅
Codex	Thread snapshot wire	7.1 KiB	7.1 KiB	+5 B (+0.1%)	7.3 KiB	✅
Codex	Live turn WebSocket wire	6.4 KiB	6.5 KiB	+37 B (+0.6%)	7.8 KiB	✅
Codex	Live turn WebSocket decoded	56.2 KiB	56.3 KiB	+44 B (+0.1%)	66.4 KiB	✅
Codex	Live turn messages	9	10	+1 (+11.1%)	21	✅
Claude	Total thread wire	13.5 KiB	13.6 KiB	+41 B (+0.3%)	15.1 KiB	✅
Claude	Thread snapshot wire	7.1 KiB	7.1 KiB	−8 B (−0.1%)	7.3 KiB	✅
Claude	Live turn WebSocket wire	6.4 KiB	6.5 KiB	+49 B (+0.7%)	7.8 KiB	✅
Claude	Live turn WebSocket decoded	57.0 KiB	57.1 KiB	+44 B (+0.1%)	66.4 KiB	✅
Claude	Live turn messages	9	10	+1 (+11.1%)	21	✅

Baseline: 7b84431 · PR result: d294419 · Source CI: success

Scenario and decoded snapshot size

10 historical turns, 5 command tools per turn, 878.9 KiB retained MCP result per historical turn, and a 1.05 MiB retained result in the measured turn.

• Codex decoded thread snapshot: 114.0 KiB
• Claude decoded thread snapshot: 114.7 KiB

Updated in place by a trusted workflow. PR artifacts are strictly validated and never executed.

[macroscopeapp]

Approvability

Verdict: Approved at d294419

Macroscope's review found this PR approvable — This is a narrowly scoped connection-compatibility bug fix that prevents relay discovery results from disabling direct servers sharing an environment ID, while preserving relay compatibility enforcement. A focused regression test covers both paths, and no defaults, schemas, deployment settings, or static-analysis rules are changed.

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