fix(clients): hold the discovered machine icon across relay refreshes

[juliusmarminge]

Follow-up to #12026, which merged before this landed on its branch.

Relay discovery empties its environment map at the start of every refresh, so a saved-but-unreached T3 Connect row (unsupported, or not yet connected) blinked from its detected glyph back to the generic server icon and forward again on each refresh. Web and mobile rows now hold the last descriptor they saw.

Also two cleanups on the web saved row: a dead || unsupported guard on the subtitle tone (unsupported is muted since #12026), and the unsupported tooltip falls back to "Client not supported" instead of "Switched off" if the compatibility text is ever absent.

No visual change beyond removing the blink, so no screenshots. Verified with typecheck for web and mobile and the cloud list / presentation / contracts tests.

Claude Fable 5.1 via Claude Code in T3 Code.

🤖 Generated with Claude Code

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Summary by CodeRabbit

• Bug Fixes
  • Environment icons now remain accurate during temporary discovery interruptions instead of reverting to generic symbols.
  • Unsupported environments no longer display misleading error-colored status text or switched-off messaging; their tooltips now show the relevant connection error or standard status.

[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	13.6 KiB	13.6 KiB	−19 B (−0.1%)	15.1 KiB	✅
Codex	Thread snapshot wire	7.1 KiB	7.0 KiB	−17 B (−0.2%)	7.3 KiB	✅
Codex	Live turn WebSocket wire	6.6 KiB	6.6 KiB	−2 B (−0.0%)	7.8 KiB	✅
Codex	Live turn WebSocket decoded	57.1 KiB	57.1 KiB	0 B (0.0%)	66.4 KiB	✅
Codex	Live turn messages	10	10	0 (0.0%)	21	✅
Claude	Total thread wire	13.6 KiB	13.6 KiB	+30 B (+0.2%)	15.1 KiB	✅
Claude	Thread snapshot wire	7.1 KiB	7.1 KiB	−2 B (−0.0%)	7.3 KiB	✅
Claude	Live turn WebSocket wire	6.5 KiB	6.6 KiB	+32 B (+0.5%)	7.8 KiB	✅
Claude	Live turn WebSocket decoded	57.8 KiB	57.9 KiB	+44 B (+0.1%)	66.4 KiB	✅
Claude	Live turn messages	9	10	+1 (+11.1%)	21	✅

Baseline: c1b2ed6 · PR result: 74a3e9c · 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: 113.9 KiB
• Claude decoded thread snapshot: 114.6 KiB

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

[macroscopeapp]

Approvability

Verdict: Approved at 74a3e9c

Macroscope's review found this PR approvable — This is a narrowly scoped client UI fix that preserves discovered machine icons across relay refreshes and improves unsupported connection messaging. Its runtime impact is limited to connection-row presentation, with no schema, infrastructure, security, billing, or static-analysis changes.

^{You can add or adjust custom eligibility rules. Learn more.}

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Team

Run ID: 795fa604-d8a2-4eb4-bc07-9960a180b57d

📥 Commits

Reviewing files that changed from the base of the PR and between c1b2ed6 and 74a3e9c.

📒 Files selected for processing (2)

• apps/mobile/src/features/connection/CloudEnvironmentRows.tsx
• apps/web/src/components/settings/ConnectionsSettings.tsx

Included review availability: Your plan provides up to 10 included reviews per hour; 7 remain after this review.

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📝 Walkthrough

Walkthrough

Connection rows now retain the last defined environment descriptor across temporary discovery gaps. Web rows also use standard status styling and tooltip text for unsupported environments.

Changes

Environment descriptor retention

Layer / File(s)	Summary
Mobile descriptor fallback apps/mobile/src/features/connection/CloudEnvironmentRows.tsx	The row retains the latest defined discovery descriptor and uses it when current discovery data is unavailable.
Web descriptor and status handling apps/web/src/components/settings/ConnectionsSettings.tsx	The row retains the latest relay descriptor. Unsupported environments no longer use error-colored status text, and their tooltip shows the connection error or connection status.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix

Suggested reviewers: t3dotgg

Merge Risk: ⚪ Minimal · up to 74a3e

No actionable issue remains in the reviewed changes.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly summarizes the main change: preserving the discovered machine icon across relay refreshes.
Description check	✅ Passed	The description explains what changed, why it changed, the lack of visual changes, and the verification performed. It does not include the template checklist, but the required information is otherwise…
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 2 functions across 2 files.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

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• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch tone-down-unsupported-follow-up

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