feat(FN-3020): merge fusion/fn-3020

Commits merged:
- test(FN-3020): complete Step 2 — lock quick-chat mobile tool-call scoping
- feat(FN-3020): complete Step 1 — scope quick-chat mobile tool-call row styles
- feat(FN-3020): complete Step 4 — document compact quick-chat tool-call rows
- fix(FN-3020): restore custom provider type compatibility for typecheck
- test(FN-3020): complete Step 2 — add quick-chat mobile tool-call regressions
- feat(FN-3020): complete Step 1 — keep compact tool-call rows single-line

Files changed:
docs/dashboard-guide.md                            |  1 +
 .../quick-chat-tool-calls-mobile-layout.test.ts    | 46 ++++++++++++++++++++++
 .../app/components/CustomProvidersSection.tsx      | 25 +++++++++++-
 packages/dashboard/app/components/QuickChatFAB.css | 37 +++++++++++++----
 packages/dashboard/app/components/QuickChatFAB.tsx |  7 ++--
 .../app/components/__tests__/QuickChatFAB.test.tsx | 18 +++++++--
 6 files changed, 119 insertions(+), 15 deletions(-)

Fusion-Task-Id: FN-3020

docs/dashboard-guide.md

@@ -47,6 +47,7 @@ Quick Chat is an optional floating panel for fast, project-scoped assistant conv
 - `switchSession()` resumes the existing thread for the selected target (agent-only or agent+model)
 - `startFreshSession()` is the explicit new-thread action and always creates a new persisted session
 - Resume lookups use a targeted session query instead of loading the full active session list first
+- Tool-call summaries in the floating quick-chat panel are intentionally condensed into a single-line header row (especially on small screens) so tool name + status stay scannable without multi-line wrapping
 
 ## Mailbox View