Project Workspace view, abort button, session invalidation, workspace fixes

Workspace (/workspace/:projectId):
- Three-panel layout (tasks / chat / notes) with CSS grid collapse toggles
- WorkspaceTaskPanel: tasks grouped by milestone, collapsible groups, task
  detail slide-over with status cycling, TaskLogSection work log, and
  inline-confirm delete
- WorkspaceNoteEditor: list view (sorted by updated_at, inline tag pills,
  inline-confirm delete) with editor view (TipTap, TagInput, Suggest tags,
  60s autosave)
- Persistent workspace conversation stored in localStorage per project;
  reused on return visits
- Thinking enabled (think: true) with Reasoning block in streaming bubble
- workspace_project_id backend pipeline: chat.py → generation_task.py →
  llm.py; system prompt uses project title so agent passes project="Title"
  to tools (fixes create_note failing with numeric project string)
- SSE tool-call watcher bridges agent actions to panel updates
- Height fix: workspace-root uses height 100%; app-content switches to
  overflow hidden via :has() selector
- Entry point: "Open Workspace" button on ProjectView

Abort button:
- Stop button in ChatView header and WorkspaceView input bar
- Calls existing cancelGeneration() / POST .../generation/cancel

Session invalidation:
- POST /api/auth/invalidate-sessions bumps session_version, keeps current
  session alive; useful after SSO/OAuth password rotation
- Button in Settings → Active Sessions section

Other:
- Dashboard recent notes limit increased from 8 to 16
- Workspace chat abort replaces Send button while streaming

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/fabledassistant/services/llm.py

@@ -451,6 +451,7 @@ async def build_context(
     include_note_ids: list[int] | None = None,
     excluded_note_ids: list[int] | None = None,
     rag_project_id: int | None = None,
+    workspace_project_id: int | None = None,
 ) -> tuple[list[dict], dict]:
     """Build messages array for Ollama with system prompt and context.
 
@@ -637,6 +638,22 @@ async def build_context(
                 f"\n\n--- Content from {url} ---\n{content}\n--- End URL Content ---"
             )
 
+    # Inject workspace context when user is in a project workspace
+    if workspace_project_id is not None:
+        from fabledassistant.services.projects import get_project
+        try:
+            wp = await get_project(user_id, workspace_project_id)
+            if wp:
+                system_parts.append(
+                    f"\n\n--- Active Workspace ---\n"
+                    f"You are in the \"{wp.title}\" project workspace.\n"
+                    f"All notes and tasks you create or update MUST belong to this project.\n"
+                    f"Always pass project=\"{wp.title}\" when calling create_note or create_task.\n"
+                    f"--- End Active Workspace ---"
+                )
+        except Exception:
+            logger.warning("Failed to fetch workspace project %d", workspace_project_id)
+
     # Inject compressed summary of older exchanges when history has been trimmed
     if history_summary:
         system_parts.append(