FN-7152: close Quick Chat on outside clicks

Quick Chat now dismisses from page clicks while other floating windows stay persistent.

- Add an opt-in outside-pointer dismissal path to FloatingWindow with safeguards for inside clicks, nested dialogs, touch compatibility events, and active drag/resize gestures.
- Enable outside-click dismissal only for the Quick Chat floating window and document the behavior.
- Cover the opt-in behavior, default persistence, nested surfaces, gesture guards, and listener cleanup with FloatingWindow tests.
- Add a release changeset for the Quick Chat dismissal feature.

Files changed:
 .changeset/fn-7152-quick-chat-outside-click-close.md      |   7 ++
 docs/dashboard-guide.md                                    |   1 +
 packages/dashboard/app/App.tsx                             |   4 +
 packages/dashboard/app/components/FloatingWindow.css       |   5 +-
 packages/dashboard/app/components/FloatingWindow.tsx       |  45 +++++++++
 packages/dashboard/app/components/__tests__/FloatingWindow.test.tsx | 109 +++++++++++++++++++++
 6 files changed, 170 insertions(+), 1 deletion(-)

Fusion-Task-Id: FN-7152
Fusion-Task-Lineage: 5bd6c10a-3e21-4eb9-bd1e-99f3aaf9c7b6
Co-authored-by: Fusion (runfusion.ai) <noreply@runfusion.ai>

docs/dashboard-guide.md

@@ -411,6 +411,7 @@ Quick Chat is an optional fast, project-scoped assistant surface for conversatio
 - Submitting the inline chooser uses explicit fresh-session creation and immediately persists/selects the new thread, then refreshes the session dropdown list
 - On first open for a project, Quick Chat restores the last opened non-archived session from per-project local storage; if that saved session is missing, it falls back to the most recently touched non-archived session by latest activity (`max(lastMessageAt, updatedAt)`), and only falls back to the first agent / configured default model when no prior session exists.
 - Closing and reopening Quick Chat keeps the active conversation warm in memory, so messages stay visible without a conversation reload or "Loading conversation…" flash.
+- Clicking outside the desktop Quick Chat floating window closes it; task pop-out floating windows remain persistent on page clicks.
 - Queued follow-up messages entered while a Quick Chat response is still streaming now persist per session, so closing/reopening the panel restores the queued stack and flushes the messages one at a time in FIFO order as active responses complete.
 - Resume lookups still use targeted session queries 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