[Yarden-zamir]

🤖 Merges pingdotgg/t3code main (73 upstream commits) into the fork. Upstream merged the linked environments stack that the fork had adopted (pingdotgg#16653 to pingdotgg#16719), so the adopted list is now empty.

Decision still open

The question below, from the first round of this pull request, is not answered yet. This merge keeps option A (both run, no code change). Options B and C stay possible as a follow-up.

pingdotgg#24741 "feat(mobile): add a 'Use last project' preference for new threads" overlaps the fork setting mobileNewThreadProject. Upstream's device preference decides first; the fork setting applies only when the project list still opens.

Behavior changes

• Linked environments: the fork now runs upstream's merged link code. Arrows still give the links (MachinePeers), and manual links still refuse. The fork hides upstream's t3_environment_link and t3_environment_unlink tools; agent texts say that links come from arrows on the machine map. Upstream gates links with the Labs setting linkedEnvironmentsEnabled (off by default) on each machine. Without it, agents cannot reach other machines.
• @ menu and send check: they use upstream's linked environments instead of the fork's readable machines list. Load balancing still uses the readable machines list.
• Thread links: agents append #<messageId> to a thread's link as given. Agents now write upstream's t3-thread://v2/<environmentId>/<threadId> links. The fork #<messageId> fragment works on v1 and v2 links. Upstream shows every thread link as a chip; threadLinkChips now only adds chips for thread addresses and app links.
• Queue: upstream's simpler Send now row replaces the fork Steer/Send button per message. The fork "Queue paused" row stays.
• Background work banner: upstream's new banner. A fork hook (withBackgroundWorkDetails) adds the details popover with task names and output files to its icon.

Breaking changes

• The fork client setting snoozeQuickOptions is removed. Upstream now has snooze presets in Settings (feat(threads): choose your own snooze options in settings pingdotgg/t3code#26208). Saved fork quick options are lost; set the choices again in upstream's setting.
• Linked environments stop working on a machine until linkedEnvironmentsEnabled is on there. Set it through the machine map before the update reaches the machines.
• Mobile: an invite enroll error now shows in the pairing form, not in the shared connection error.

Conflicts and resolution

About 130 files conflicted. Stack files take upstream's version, then the fork hooks apply again: MachinePeers and cliLinks.ts implement the new PeerLinks.enabled and describe, the CLI refusal layer stays, and Settings shows the arrow links. Other files merge both sides. Upstream deleted unreached code (pingdotgg#26238); fork code that used it gets it back (useEnvironmentIds, two mobile settings rows, some type exports) or drops it (serverGetSettings, terminal.restart, clearConnectionCatalog).

Fork fixes

• Fork effects follow upstream's new rule that each React effect states its reason. Effects in upstream files got reasons; 45 fork files keep the rule at warn (vite.config.ts) until their effects state reasons. scripts/fork-effect-budget.json is gone with upstream's budget rule.
• excludedUpstreamTests.ts is empty: upstream main has the link migrations.
• Docs: docs/fork/operations.md, docs/fork/features.md, README.md, apps/machine-map/SPEC.md (MM-1906, MM-1907) follow the changes above.

Checks

• checks.py: typecheck, migration check, adopted pull request check, format, lint and knip pass.
• fork_tests.py: all 273 fork test files pass locally after the fixes. Fork CI runs the full suites.
• "Agent context budget" (not required) fails: the measured MCP tool list grows by 680 bytes over main. Most of it is upstream's two link tools, which the test counts although the fork hides them from agents. The Claude and Codex instructions shrink by 108 bytes each. The committed budget has the new values; the check passes only with the agent-context-increase label, which a maintainer adds.

Fork repair skill changes

None.

[Yarden-zamir]

🤖 Independent review (head 2557f096234f): changes needed.

1. Medium: upstream's t3_environment_link tool creates a pairing card that always ends in MANUAL_LINK_REFUSAL in the fork. Fix: hide the link tools; fix the texts that point agents at them.
2. Medium: forkThreadLinkInstructions.ts:7 still taught v1 message links; cross-machine message links could open nothing.
3. Low: the fork's background-work details (task names, output files, icon popover) were lost under upstream's new banner, while docs/fork/features.md still described them.
4. Low: removing "Snooze quick options" is breaking; the title needs !.
5. Low: linkedEnvironmentsEnabled must be on before the update reaches the machines (set through the machine map, revision 675).
6. Decision: mobileNewThreadProject overlaps upstream's "Use last project"; option A kept (both run, upstream decides first).

Confirmed: fork hooks intact (236 files before and after), every deleted fork file has a reason, migrations 70 to 72 do not collide.
Fixed in 3acafb866a9b: 1 to 4.