Stream model pull progress via SSE instead of fire-and-forget

Replace the asyncio.create_task() fire-and-forget pattern for model
downloads with SSE streaming that relays Ollama's pull progress in
real time. The frontend now shows live download percentage instead of
a static "Pulling..." label with blind polling.

- routes/chat.py: SSE streaming endpoint with 1800s timeout
- stores/settings.ts: pullModel uses apiStreamPost with onProgress callback
- SettingsView.vue: live "Downloading 42%" display, removed polling/setTimeout
- summary.md: updated to reflect SSE streaming for model pulls

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

summary.md

@@ -66,9 +66,10 @@ for AI-assisted features.
   simple word splitting with stopword filtering (no embeddings).
 - **No blocking long-running operations:** Any potentially slow operation (model
   pulls, LLM calls, URL fetching, etc.) must never block app startup or freeze the
-  UI. Backend uses `asyncio.create_task()` for fire-and-forget work and SSE streaming
-  for incremental responses. Frontend keeps the UI responsive during async operations
-  (loading states, streaming indicators). This applies to all future features as well.
+  UI. Backend uses SSE streaming for incremental responses (chat messages and model
+  pull progress). Frontend keeps the UI responsive during async operations (loading
+  states, streaming indicators, progress percentages). This applies to all future
+  features as well.
 - **Auto-pull model on startup:** Non-blocking background task, logs warning on
   failure so the app still starts even if Ollama isn't ready.
 - **Backlinks:** `GET /api/notes/:id/backlinks` searches all note bodies for
@@ -209,7 +210,7 @@ fabledassistant/
     │   │   ├── notes.ts         # CRUD + tag filter, resolveTitle, convertToTask, convertToNote, fetchBacklinks, fetchAllTags
     │   │   ├── tasks.ts         # CRUD + status/priority filter, patchStatus (uses body not description)
     │   │   ├── chat.ts          # Conversation CRUD, sendMessage (SSE streaming), saveMessageAsNote, summarizeAsNote, fetchModels, status polling (ollamaStatus, modelStatus, chatReady)
-    │   │   ├── settings.ts      # App settings: assistantName, defaultModel, fetchInstalledModels, pullModel, deleteModel
+    │   │   ├── settings.ts      # App settings: assistantName, defaultModel, fetchInstalledModels, pullModel (SSE streaming with onProgress callback), deleteModel
     │   │   └── toast.ts         # Toast notification state, 3s auto-dismiss
     │   ├── types/
     │   │   ├── note.ts          # Note interface (with status, priority, due_date, is_task) + TaskStatus, TaskPriority types + NoteListResponse
@@ -279,7 +280,7 @@ fabledassistant/
 | POST | `/api/chat/conversations/:id/summarize` | Summarize conversation via LLM, save as note |
 | GET | `/api/chat/status` | Check Ollama availability and model readiness (`{ollama, model, default_model}`) |
 | GET | `/api/chat/models` | List available Ollama models |
-| POST | `/api/chat/models/pull` | Pull/download a model from Ollama (background, body: `{model}`) |
+| POST | `/api/chat/models/pull` | Pull/download a model from Ollama via SSE streaming progress (body: `{model}`, response: SSE with `{status, completed, total}` events) |
 | POST | `/api/chat/models/delete` | Delete a model from Ollama (body: `{model}`) |
 | GET | `/api/settings` | Get all app settings as `{key: value}` dict |
 | PUT | `/api/settings` | Update settings (body: `{key: value, ...}`) |
@@ -441,7 +442,7 @@ When adding a new migration, follow these conventions:
 - [x] **Configurable assistant name:** Default "Fable", editable in settings, injected into LLM system prompt and chat message labels
 - [x] **Settings page:** `/settings` route with assistant name form + model catalog
 - [x] **Model catalog:** 18 models across 3 categories (General Purpose, Coding, Uncensored / Creative Writing) with descriptions, sizes, and best-for labels
-- [x] **Model management:** Download (pull), select (set as default), and remove (delete from Ollama) with confirmation UI
+- [x] **Model management:** Download (pull with SSE progress streaming + live percentage in UI), select (set as default), and remove (delete from Ollama) with confirmation UI
 - [x] **Status indicator in nav bar:** Moved from per-component (ChatView/ChatPanel) to global AppHeader; green/yellow/red dot with label
 - [x] **Chat bubble layout:** User messages right-aligned (primary color bg), assistant messages left-aligned (card bg), speech bubble tails
 - [x] **Floating dark input bar:** `#1c1c1e` background, rounded corners, circular send button with arrow
@@ -485,7 +486,7 @@ When adding a new migration, follow these conventions:
 - Dedicated `/chat` page with bubble-style messages (user right, assistant left), floating dark input bar
 - Slide-out chat panel accessible from any page, auto-includes note/task context
 - Settings page: configurable assistant name (default "Fable"), model catalog with 18 models in 3 categories
-- Model management: download, select, and remove models from the settings page
+- Model management: download (with live SSE progress percentage), select, and remove models from the settings page
 - Ollama status indicator in global nav bar (green/yellow/red dot) with 30s polling
 - Recent chats section on home page with quick "New Chat" button
 - HTML entity rendering fix (apostrophes in marked → DOMPurify pipeline)