chore(upstream): sync marcode through ba9c9ae81dce, port workspace tree onto the new sidebar

[maarco]

Merges pingdotgg/t3code@ba9c9ae81dce — 140 upstream commits, 41 conflicted files, all resolved by hand.

The scheduled sync had been failing since Aug 3 (#10, #11, #12, #13, #14, #15 are all the same blockage): main never advanced past the last merge, so every daily run re-planned the same growing delta. This clears it. Supersedes #9 and #17.

field	value
upstream source	ba9c9ae81dce4e554b4dd52abfd28d0c01b5c651
previous upstream sha in main	5192f777fe54c2a2a359f6c25ecf5fbde46d49b0
merge base / target	d0c01668c0f87b10bf952f929c55c7a8ca818fdf
upstream commits	140
conflicted files	41

The sidebar

Upstream promoted sidebar v2 to the default and deleted the v1/v2 split (0de95407), colliding head-on with Marcode's unified workspace tree. Rather than keep the tree welded into their file, it now lives in a Marcode-owned component:

• unified-workspace/SidebarProjectWorkspaceSection.tsx — the whole tree, taking four stable props (which project, which thread is active, is this mobile) and sourcing thread actions, scripts and keybindings from hooks rather than accepting handlers threaded out of Sidebar.tsx's internals.
• Sidebar.tsx — one import and one mount point, both marked ── Marcode fork seam ──, with a test pinning that they stay there and stay small.

That's the difference between the next upstream sidebar rewrite conflicting on two small hunks versus 5,100 lines.

The tree renders above upstream's thread sections, so their pinning, drafts and drag-to-reorder keep working untouched, and the workspace gets its attached files/folders, URL shortcuts, commands and live terminals/browser tabs with the Add-item menu for attaching code.

Flags collapse to upstream's legacySidebarEnabled; the Marcode-only sidebarV2Enabled is gone. Marcode still renders no sidebar on settings routes — FloatingPillNav owns brand/settings, so upstream's in-sidebar SettingsSidebarNav would duplicate them.

Silent fork-boundary breaks caught

Each of these merged without a conflict and would have shipped a quietly broken Marcode:

1. Theme boot read the wrong key — upstream's new inline boot script reads localStorage["t3code:theme"]; Marcode renamed it to "marcode:theme". Every page load would have flashed the wrong theme before React mounted.
2. appearanceFonts.ts didn't mirror Marcode's fonts — it documents its stacks as mirroring index.css and shows the resolved family to users in Settings → Appearance; upstream's are system fonts, Marcode's are Inter/JetBrains.
3. --share bundled-dev speedup was inert — dev-runner sets T3CODE_BUNDLED_DEV, Marcode's vite config reads MARCODE_BUNDLED_DEV.
4. DesktopEarlyElectronStartup.ts (new) read T3CODE_HOME while every Marcode writer sets MARCODE_HOME.
5. DesktopStatePaths.ts (new) defaulted to ~/.t3 instead of ~/.marcode, feeding both early startup and DesktopEnvironment.
6. t3 pair read T3CODE_HOME — the documented pairing-token recovery command.
7. migrate-dev-db (new) imported the pre-rename resolveWorktreeT3Home and defaulted its source db to ~/.t3/userdata/state.sqlite, which doesn't exist here.
8. New boot-service test hardcoded t3code.service; Marcode's unit is marcode.service.
9. projector.ts hunks were mis-aligned — upstream's new defaultThreadEnvMode/faviconPath were aligned against Marcode's different project.workspace-layout-applied handler, so either side alone would have silently dropped them.
10. DesktopLinuxUrlHandler.test.ts (new) asserted the Linux URL handler claims x-scheme-handler/t3code; the runtime correctly registers marcode.

Migration renumbering

Marcode owns id 33 = ProjectWorkspaceLayout, so shared migrations sit one higher. Upstream's new 36–40 collided with Marcode's 36 and were shifted to 37–41 (files git mvd, registry, pin test and migration test updated). Renumbering an already-applied id would re-run or skip it on existing installs.

Other decisions

• Right panel — drops plan (upstream folded plans into the transcript), keeps Marcode's removal of file/files, adopts upstream's agents surface. Storage version 10. Both removals are now pinned by tests so a future sync fails loudly instead of silently restoring a second editing surface.
• Usage page — upstream links /usage from their sidebar footer, which Marcode keeps empty. Wired into FloatingPillNav, or the whole feature would be unreachable.
• Terminal — kept Marcode's xterm renderer, which carries terminal search that upstream's Ghostty surface lacks. Ported upstream's terminal theme tokens and Appearance font settings onto it; the Ghostty font preview got its own theme builder (terminal/ghostty/theme.ts) so a Ghostty consumer no longer imports from the xterm drawer. This divergence is a standing cost — see the note in AGENTS.md.
• ProjectScriptsControl — kept Marcode's (it carries the handle/placement API the workspace tree drives). Upstream's extraction landed independently as projectScriptEditor.tsx for their new project settings page.
• index.css — Marcode's palette with upstream's new semantic tokens folded in; followed their data-sidebar-version → data-app-sidebar rename and their move of the font tokens into a runtime-overridable @theme block.
• Chat header — upstream added a thread action menu on the title. Marcode's header shows only the title (the pill nav owns thread actions, and the sidebar row menu already provides them), so that machinery is deliberately not mounted; their pure resolveRenameCommit helper is kept with its tests.

Merge-friendliness guidance

AGENTS.md (= CLAUDE.md) gains "Write every change so the next upstream merge is cheap": add files rather than rewriting theirs, minimize coupling to their internals rather than just line count, mark the seam, take their refactors even when keeping your behavior, pin removals with tests, watch for the breaks that produce no conflict, and own the divergences you keep deliberately.

Verification

All four required checks green on e0c11584: Check, Test, Mobile Native Static Analysis, Release Smoke.

• Full workspace typecheck clean (15 packages)
• Per-package test runs: desktop 58, mobile 100, relay 27, oxlint 4, server 219, scripts 20, plus 484 focused web/client-runtime/contracts tests
• vp fmt --check and vp lint clean on every changed file
• No force push, reset, restore, stash, clean, or wholesale ours/theirs resolution

Five tests fail locally but pass in CI, all confirmed environmental and none in files this merge touches: four assert on chmod-denied access and this container runs as uid 0 (which bypasses chmod 000/400), and Net.test.ts needs an IPv6 loopback this container does not have (::1 returns EAFNOSUPPORT).

Not verified: no live browser pass — this ran headless, so the sidebar has not been seen running at 390px/820px.