feat(dashboards): production builder, native chat, shared context ring (backport #1142)

[mergify]

Summary

The dashboard builder is now a self-contained workspace: its chat never hands you off to main Chat, a build survives a page refresh, it keeps its own history and approvals, and the composer wears main chat's model picker and context ring without crowding the pane.

What changed

• Refresh-safe builds: a hard refresh restores the progress card and the reply lands without a duplicate prompt.
• Dashboard-native navigation: no "Open in chat"; hide and show chat; the Approval Board opens the exact dashboard thread, even with chat hidden.
• Own namespace: dashboard threads stay out of main chat's list and search and refuse sends from other surfaces.
• Composer parity: the shared model picker stays inside the pane; the pane mounts main chat's ContextRing and compact popover. Failed runs show their reason.
• More room: the left rail auto-collapses while the builder is open; on a phone the canvas and chat swap full-width.
• Sharing: Org and Role scopes hold for non-owners.

Risk and verification

• 1786 vitest, 839 node:test, focused backend classes and ruff green; verified live on an isolated preview (screenshots below). The local LLM pool was rate-limited, so worker-side paths were driven with seeded transcripts through this branch's worker functions.

Pre-merge checklist

ℹ️ A red check only blocks the merge where the branch ruleset lists it as required.
Honoring this checklist is what keeps broken changes out of UAT. See
CONTRIBUTING.md.

• CI is green — the tests check on this PR passes (never merge on ❌)
• Branch is up to date with its base (develop, or version-N-hotfix for a backport)
• New/changed behavior has tests (the coverage gate still passes)
• I self-reviewed the diff
• If the base is version-N: this is the release PR from version-N-hotfix, __version__ is bumped, and release-source is green

Screenshots

Live on an isolated worktree preview of this branch (e2e.localhost). Before = base branch, After = this PR.

	Before	After
Model and effort picker in the pane
Context meter in the composer
Left rail while the builder is open
Phone width (390px)

Refresh-safe build, restored after a hard refresh mid-run (new behavior, no Before):

Review-round fixes and rebase notes

Intended behavior change: a send into a dashboard thread from main Chat or Triggers now returns ok:false with a "continue in Dashboard Builder" reason.

Found and fixed while testing the builder end to end:

• The shared model picker hung its menu off the pill's right edge and its effort flyout further left, which put both outside the pane's overflow-hidden edge. New align="start" and compact props keep them inside a narrow host.
• A run that failed before its first token left an empty assistant row whose reason lived in error; the pane filtered bubbles on content, so the failure rendered as nothing and the composer silently unlocked.
• A never-titled thread carried the server's "New chat" placeholder into the history menu, where it read as the action beside it.
• The shell store called window.matchMedia at module load, which broke any spec importing a page that imports the store. Both breakpoint listeners are now guarded.
• The builder's own text context pill and lib/contextUsage are removed in favor of the shared ContextRing fed by get_conversation_context, and the context_usage snapshot that get_conversation inlined for it is dropped with its tests.

The branch was rebased onto develop after #1136 merged (zero conflicts; the pre-rebase state is kept on backup/dashboard-builder-pre-rebase). Dashboard threads are ordinary sessions to the context and compact endpoints, so nothing there is dashboard-only.

Known, out of scope: the Vue warning "Failed to resolve component: Button" on the Approval Board comes from its pre-existing FileUploader and is untouched here.

https://claude.ai/code/session_01CkvbXsZAizy4UDh9ZWjn51

---

This is an automatic backport of pull request #1142 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of f480509 has failed:

On branch mergify/bp/version-15-hotfix/pr-1142
Your branch is ahead of 'origin/version-15-hotfix' by 3 commits.
  (use "git push" to publish your local commits)

You are currently cherry-picking commit f480509.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   frontend/src/api/dashboards.js
	modified:   frontend/src/components/chat/ModelEffortPicker.spec.js
	modified:   frontend/src/components/chat/ModelEffortPicker.vue
	modified:   frontend/src/lib/dashboardBuildCard.js
	modified:   frontend/src/lib/dashboardBuildCard.test.js
	modified:   frontend/src/lib/dashboardOpen.test.js
	modified:   frontend/src/lib/dashboardProductionBoundary.test.js
	modified:   frontend/src/lib/dashboardRestore.test.js
	modified:   frontend/src/notify/globalNotifier.js
	modified:   frontend/src/pages/approvals/ApprovalsBoard.vue
	modified:   frontend/src/pages/dashboards/DashboardChatPane.vue
	modified:   frontend/src/pages/dashboards/DashboardView.vue
	modified:   frontend/src/pages/dashboards/DashboardsPage.vue
	modified:   frontend/src/stores/shell.js
	modified:   jarvis/chat/api.py
	modified:   jarvis/chat/chat_asks.py
	modified:   jarvis/chat/events.py
	modified:   jarvis/tests/test_chat_asks.py
	modified:   jarvis/tests/test_chat_events.py
	modified:   jarvis/tests/test_dashboards_api.py

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   jarvis/chat/list_registry.py

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally