feat(web): multi-select projects in the sidebar scope picker

[Andreas-Froyland]

What Changed

The project scope picker in the thread sidebar now supports selecting multiple projects at once:

• CTRL/CMD-click (or CTRL/CMD+Enter) toggles a project into a multi-scope while the popup stays open, and the search query survives toggling.
• Plain click keeps the existing single-project behavior, and "All projects" resets the scope. Marked projects highlight inside the popup.
• The trigger shows the selected project names joined with ", ", and once several projects make that label truncate, hovering the picker shows a tooltip with the full list.
• The whole scope set persists, so navigating to Settings or restarting the app restores every selected project rather than just one.

Why

I am often working on multiple repos that are connected, as well as using T3 Code for different purposes on different computers, while still sharing one account. The single-project scope hid work that was spread across related projects, and this keeps the single-project workflow intact while letting a multi-scope show everything at once.

Merging with main

Two changes landed on main after this branch opened and both touched the same code, so this now builds on top of them rather than reverting them:

• fix(web): keep the sidebar project filter across navigation #9416 moved the scope into the persisted UI store as a single sidebarProjectScopeKey. That field is now sidebarProjectScopeKeys: string[]; parsePersistedState still reads the old singular key once, so installs that saved a filter before this PR keep it. The "scoped project vanished" reset keeps its useAllEnvironmentProjectSnapshotsReady() gate, which matters more now — without it a persisted scope would be pruned on every cold start while environments are still connecting.
• fix(web): make sidebar project actions reachable by keyboard and screen reader #5521 added keyboard and screen-reader access to project settings from the picker. Its onItemHighlighted and suppressNextScopeChangeRef guards are preserved inside the new onValueChange. The guard is load-bearing here: on macOS a CTRL+click fires contextmenu and opens project settings, and without it that same press would also toggle the project into the scope.

UI Changes

Before — one project at a time:

After — CTRL+click marks additional projects while the popup stays open:

After — the closed picker joins the selected names (truncated when long):

Hovering the picker reveals every selected project:

Full interaction (video): project-multi-select.webm

Checklist

• This PR is small and focused
• I explained what changed and why
• I included before/after screenshots for any UI changes
• I included a video for animation/interaction changes

Verification:

• vp test run apps/web/src/components/Sidebar.logic.test.ts apps/web/src/uiStateStore.test.ts — 147 passed, including tests for the press resolver (resolveSidebarProjectScopePress) and for the persisted scope array, its dedup, and the migration from the legacy single key
• vp run --filter @t3tools/web typecheck — clean
• vp lint apps/web/src/components/Sidebar.tsx — 24 warnings, identical to the main baseline measured on the same file

Worked on by GLM-5.3-flash via T3 Code (opencode). Merged with main and conflicts resolved by Claude Opus 5 via T3 Code.

Closes discussions

• Sidebar: let the project scope picker hold more than one project #10500

Note

Add multi-select project scope to Sidebar picker

• Changes sidebar project scope from a single nullable key to a persisted array of keys in uiStateStore.ts; plain clicks select one project and close the menu, CTRL/CMD clicks toggle projects without closing, and All projects clears the scope.
• Thread filtering now builds a union of member project references across all selected groups, and unavailable persisted projects are pruned once project snapshots are ready.
• Adds sanitizeSidebarProjectScopeKeys migration so legacy single-key state hydrates into a one-element array, while an explicitly stored new array takes precedence.
• Risk: PersistedUiState keeps the old nullable scope field read-only for migration; consumers still reading the old setSidebarProjectScopeKey action or nullable scope property must move to setSidebarProjectScopeKeys and the array field.

^{Macroscope summarized 2589fd4.}

Summary by CodeRabbit

• New Features

  • Filter threads by one or multiple projects using the sidebar project picker.
  • Use Cmd/Ctrl-click or Enter to select multiple projects while keeping the picker open.
  • Project filters persist across navigation and app restarts, with unavailable projects removed automatically.
  • Select All projects to clear the filter.
  • Empty results now clarify whether no threads match one project or multiple projects.

• Documentation

  • Added guidance for searching, selecting, and clearing project filters.

[macroscopeapp]

Approvability

Verdict: Not approved

Macroscope's review found this PR not approvable — This PR introduces modifier-based multi-project selection, persistent scope migration, and broader sidebar filtering behavior across existing thread views. The cross-platform interaction and expanded runtime surface should be manually validated.

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

[IARI]

This solves my exact use case: I regularly have paused or unsettled threads across many projects, but actively work in only two or three at a time. “All projects” creates too much noise, while a single-project scope makes me repeatedly switch filters.

I see the branch now needs a rebase against main. Once it is updated, I can manually validate the Windows desktop interaction and persistence behavior locally.

[coderabbitai]

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📝 Walkthrough

Walkthrough

The sidebar project scope now supports multiple selected projects. Scope keys persist as an array with legacy migration. Modifier presses toggle projects, plain presses select one project, and unavailable projects are pruned.

Changes

Sidebar project scope

Layer / File(s)	Summary
Persisted scope state apps/web/src/uiStateStore.ts, apps/web/src/uiStateStore.test.ts	Project scope state uses sidebarProjectScopeKeys. The store sanitizes arrays, removes duplicates, persists the array, and migrates legacy sidebarProjectScopeKey values.
Scope press resolution apps/web/src/components/Sidebar.logic.ts, apps/web/src/components/Sidebar.logic.test.ts	New helpers detect CTRL/CMD modifier presses and resolve scope changes as reset, solo, toggle, or no-op actions.
Sidebar multi-scope integration apps/web/src/components/Sidebar.tsx, docs/user/thread-sidebar.md	The project combobox supports multiple selections. The sidebar derives multi-project labels and groups, prunes unavailable keys, resets settled-tail state from sorted keys, and documents the selection behavior.

Priority: ➖ Normal

Estimated code review effort: 3 (Moderate) | ~30 minutes

Change: Feature

Sequence Diagram(s)

sequenceDiagram
  participant User
  participant Sidebar
  participant SidebarLogic
  participant UiStateStore
  User->>Sidebar: Select project with plain or modifier press
  Sidebar->>SidebarLogic: Resolve project scope press
  SidebarLogic-->>Sidebar: Return reset, solo, toggle, or null
  Sidebar->>UiStateStore: Set sidebarProjectScopeKeys
  UiStateStore-->>Sidebar: Update persisted scope state

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Suggested reviewers: juliusmarminge

Merge Risk: ⚪ Minimal · up to e2f3a

The picker remains open for modifier-based multi-selection, with no confirmed merge-blocking issue in the reviewed change.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 25.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 12 functions across 5 files. (1 skipped: …	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely describes the main change: adding multi-select support to the web sidebar project scope picker.
Description check	✅ Passed	The description includes What Changed, Why, UI evidence, checklist completion, verification results, migration details, and related context. It is complete and directly related to the pull request.
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.

Full details: Docstring Coverage

Explanation

Docstring coverage is 25.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 12 functions across 5 files. (1 skipped: 1 unsupported.)

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Actionable comments posted: 2

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Inline comments:
In `@apps/web/src/components/Sidebar.tsx`:
- Line 4435: Update the resolver call near previousKeys to use the controlled
visible combobox values from selectedProjectScopeItems rather than the full
persisted projectScopeKeys array. Preserve the existing follow-up behavior that
updates the full persisted keys after resolving the selection.

In `@docs/user/thread-sidebar.md`:
- Around line 110-126: Run the required Markdown formatter with vp check --fix
and ensure the thread-sidebar documentation remains formatter-clean.

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• apps/web/src/components/Sidebar.logic.test.ts
• apps/web/src/components/Sidebar.logic.ts
• apps/web/src/components/Sidebar.tsx
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• apps/web/src/uiStateStore.ts
• docs/user/thread-sidebar.md

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