refactor: Cleanup git state - commit all staged changes

Major refactoring cleanup:
- Add new controller architecture (class-controller-*.php)
- Add new settings-v2 UI (views/settings-v2/)
- Add new CSS architecture (agentic-sidebar.css, tokens)
- Add esbuild build pipeline (scripts/build.js, package.json)
- Add composer dependencies (vendor/)
- Add frontend src directory (assets/js/src/index.jsx)
- Add documentation files
- Remove old/obsolete files (class-settings.php, old CSS)

This commits all pending changes from previous refactoring efforts.

docs/architecture/REST_API_ENDPOINTS.md

@@ -0,0 +1,720 @@
+# REST API Endpoints
+
+Complete reference for WP Agentic Writer REST API endpoints.
+
+**Base URL:** `/wp-json/wp-agentic-writer/v1`
+
+**Authentication:** All endpoints require WordPress authentication via `cookie` or application password. Permission checks vary by endpoint (see below).
+
+**Rate Limiting:** Most endpoints are rate-limited. See [Rate Limits](#rate-limits) below.
+
+---
+
+## Rate Limits
+
+| Endpoint | Limit | Window | Notes |
+|----------|-------|--------|-------|
+| `POST /chat` | 30/min | 60s | |
+| `POST /chat_stream` | 30/min | 60s | Streaming variant |
+| `POST /search` | 20/min | 60s | Brave Search |
+| `POST /fetch-content` | 10/min | 60s | Web content fetch |
+| All others | — | — | No rate limiting |
+
+---
+
+## Models
+
+### `GET /models`
+
+List available AI models from OpenRouter.
+
+**Handler:** `Controller_Models::handle_get_models()`
+
+**Permission:** `check_permissions` (authenticated user)
+
+**Response:** Array of model objects from OpenRouter cache.
+
+---
+
+### `POST /models/refresh`
+
+Force-refresh the model cache.
+
+**Handler:** `Controller_Models::handle_refresh_models()`
+
+**Permission:** `check_permissions`
+
+**Response:**
+```json
+{
+  "models": [...],
+  "message": "Models refreshed successfully."
+}
+```
+
+---
+
+## Chat
+
+### `POST /chat`
+
+Send a chat message (non-streaming).
+
+**Handler:** `Controller_Chat::handle_chat_request()`
+
+**Permission:** `check_permissions` + post edit (if `postId` provided)
+
+**Rate Limit:** 30 requests/minute
+
+**Request Body:**
+```json
+{
+  "messages": [...],
+  "postId": 123,
+  "sessionId": "uuid",
+  "type": "planning|writing|revising",
+  "stream": false
+}
+```
+
+**Response:** Full JSON response with assistant message.
+
+---
+
+### `POST /chat` (streaming variant)
+
+Same endpoint with `"stream": true` in request body. Uses Server-Sent Events.
+
+**Rate Limit:** 30 requests/minute (same as non-streaming)
+
+**Response:** `text/event-stream` with chunks.
+
+---
+
+### `POST /clear-context`
+
+Clear the chat context for a post.
+
+**Handler:** `Controller_Chat::handle_clear_context()`
+
+**Permission:** `check_permissions` + post edit
+
+**Request Body:**
+```json
+{
+  "postId": 123,
+  "sessionId": "uuid"
+}
+```
+
+---
+
+### `GET /chat-history/(?P<post_id>\d+)`
+
+Get legacy chat history from post meta. **Deprecated** — use `/conversations` instead.
+
+**Handler:** `Gutenberg_Sidebar::handle_get_chat_history()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+## Conversations
+
+### `GET /conversation/(?P<post_id>\d+)`
+
+Get canonical conversation for chat hydration.
+
+**Handler:** `Gutenberg_Sidebar::handle_get_conversation()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+### `GET /conversations`
+
+List all conversations for the current user.
+
+**Handler:** `Gutenberg_Sidebar::handle_get_conversations()`
+
+**Permission:** `check_permissions`
+
+---
+
+### `GET /conversations/post/(?P<post_id>\d+)`
+
+List conversations linked to a specific post.
+
+**Handler:** `Gutenberg_Sidebar::handle_get_conversations()`
+
+**Permission:** `check_permissions`
+
+---
+
+### `POST /conversations`
+
+Create a new conversation.
+
+**Handler:** `Gutenberg_Sidebar::handle_create_conversation()`
+
+**Permission:** `check_permissions`
+
+---
+
+### `GET /conversations/(?P<session_id>[a-zA-Z0-9]+)`
+
+Get a specific conversation.
+
+**Handler:** `Gutenberg_Sidebar::handle_get_conversation()`
+
+**Permission:** `check_permissions`
+
+---
+
+### `PUT /conversations/(?P<session_id>[a-zA-Z0-9]+)`
+
+Update conversation metadata.
+
+**Handler:** `Gutenberg_Sidebar::handle_update_conversation()`
+
+**Permission:** `check_permissions`
+
+---
+
+### `DELETE /conversations/(?P<session_id>[a-zA-Z0-9]+)`
+
+Delete a conversation.
+
+**Handler:** `Gutenberg_Sidebar::handle_delete_conversation()`
+
+**Permission:** `check_permissions`
+
+---
+
+### `POST|PUT /conversations/(?P<session_id>[a-zA-Z0-9]+)/messages`
+
+Add or update messages in a conversation.
+
+**Handler:** `Gutenberg_Sidebar::handle_update_conversation_messages()`
+
+**Permission:** `check_permissions`
+
+---
+
+### `POST /conversations/(?P<session_id>[a-zA-Z0-9]+)/link-post`
+
+Link a conversation to a post.
+
+**Handler:** `Gutenberg_Sidebar::handle_link_conversation_to_post()`
+
+**Permission:** `check_permissions`
+
+---
+
+### `POST /conversations/(?P<session_id>[a-zA-Z0-9]+)/lock`
+
+Acquire or refresh session lock (heartbeat).
+
+**Handler:** `Controller_Session::handle_session_lock()`
+
+**Permission:** `check_permissions` + conversation access
+
+**Request Body:**
+```json
+{
+  "tab_id": "uuid",
+  "force": false
+}
+```
+
+**Response:**
+```json
+{
+  "acquired": true,
+  "expires_at": 1234567890,
+  "tab_id": "uuid"
+}
+```
+
+---
+
+### `DELETE /conversations/(?P<session_id>[a-zA-Z0-9]+)/lock`
+
+Release session lock.
+
+**Handler:** `Controller_Session::handle_session_unlock()`
+
+**Permission:** `check_permissions` + conversation access
+
+---
+
+## Planning & Writing
+
+### `GET|POST /post-config/(?P<post_id>\d+)`
+
+Get or save post configuration (focus keyword, language, article type).
+
+**Handler:** `Gutenberg_Sidebar::handle_get_post_config()` / `handle_save_post_config()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+### `POST /generate-plan`
+
+Generate article outline/plan.
+
+**Handler:** `Gutenberg_Sidebar::handle_generate_plan()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+### `POST /revise-plan`
+
+Revise an existing plan.
+
+**Handler:** `Gutenberg_Sidebar::handle_revise_plan()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+### `POST /execute-article`
+
+Execute article generation from plan.
+
+**Handler:** `Gutenberg_Sidebar::handle_execute_article()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+### `POST /reformat-blocks`
+
+Reformat blocks (e.g., convert to different structure).
+
+**Handler:** `Gutenberg_Sidebar::handle_reformat_blocks()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+### `POST /regenerate-block`
+
+Regenerate a single block.
+
+**Handler:** `Gutenberg_Sidebar::handle_regenerate_block()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+### `POST /refine-block`
+
+Refine a block with instructions.
+
+**Handler:** `Gutenberg_Sidebar::handle_block_refine()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+### `POST /refine-from-chat`
+
+Refine blocks based on chat conversation.
+
+**Handler:** `Gutenberg_Sidebar::handle_refine_from_chat()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+### `POST /refine-multi-pass`
+
+Multi-pass block refinement.
+
+**Handler:** `Gutenberg_Sidebar::handle_refine_multi_pass()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+### `POST /refine-article`
+
+Article-wide refinement.
+
+**Handler:** `Gutenberg_Sidebar::handle_refine_article()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+### `POST /summarize-context`
+
+Summarize context to stay within token limits.
+
+**Handler:** `Gutenberg_Sidebar::handle_summarize_context()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+## Content Quality
+
+### `POST /check-clarity`
+
+Check content clarity.
+
+**Handler:** `Gutenberg_Sidebar::handle_check_clarity()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+### `POST /detect-intent`
+
+Detect user intent from message.
+
+**Handler:** `Gutenberg_Sidebar::handle_detect_intent()`
+
+**Permission:** `check_permissions`
+
+---
+
+### `POST /suggest-improvements`
+
+Proactive improvement suggestions (idle analysis).
+
+**Handler:** `Gutenberg_Sidebar::handle_suggest_improvements()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+## SEO
+
+### `GET /seo-audit/(?P<post_id>\d+)`
+
+Run SEO audit for a post.
+
+**Handler:** `Gutenberg_Sidebar::handle_seo_audit()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+### `POST /generate-meta`
+
+Generate meta description.
+
+**Handler:** `Gutenberg_Sidebar::handle_generate_meta()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+### `POST /suggest-keywords`
+
+Suggest keywords for a post.
+
+**Handler:** `Gutenberg_Sidebar::handle_suggest_keywords()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+### `GET /geo-score/(?P<post_id>\d+)`
+
+Get GEO scoring for a post.
+
+**Handler:** `Gutenberg_Sidebar::handle_geo_score()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+## Title & Excerpt
+
+### `POST /generate-title`
+
+Generate post title (uses WP 7.0 AI Client when available).
+
+**Handler:** `Gutenberg_Sidebar::handle_generate_title()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+### `POST /refine-title`
+
+Refine title with instructions.
+
+**Handler:** `Gutenberg_Sidebar::handle_refine_title()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+### `POST /generate-excerpt`
+
+Generate post excerpt (uses WP 7.0 AI Client when available).
+
+**Handler:** `Gutenberg_Sidebar::handle_generate_excerpt()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+## Images
+
+### `GET /image-recommendations/(?P<post_id>\d+)`
+
+Get image recommendations for a post.
+
+**Handler:** `Gutenberg_Sidebar::handle_get_image_recommendations()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+### `POST /generate-image`
+
+Generate an image.
+
+**Handler:** `Gutenberg_Sidebar::handle_generate_image()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+### `POST /commit-image`
+
+Commit/save generated image.
+
+**Handler:** `Gutenberg_Sidebar::handle_commit_image()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+## Writing State
+
+### `GET /writing-state/(?P<post_id>\d+)`
+
+Get writing state for a post.
+
+**Handler:** `Gutenberg_Sidebar::handle_get_writing_state()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+### `POST /writing-state/(?P<post_id>\d+)`
+
+Save writing state.
+
+**Handler:** `Gutenberg_Sidebar::handle_save_writing_state()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+## Section Blocks
+
+### `POST /section-blocks`
+
+Save section block mapping.
+
+**Handler:** `Gutenberg_Sidebar::handle_save_section_blocks()`
+
+**Permission:** `check_permissions`
+
+---
+
+### `GET /section-blocks/(?P<post_id>\d+)`
+
+Get section blocks for a post.
+
+**Handler:** `Gutenberg_Sidebar::handle_get_section_blocks()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+## Cost Tracking
+
+### `GET /cost-tracking/(?P<post_id>\d+)`
+
+Get cost tracking data.
+
+**Handler:** `Controller_Cost::handle_get_cost_tracking()`
+
+**Permission:** `check_permissions` + post edit (if `post_id` > 0)
+
+---
+
+## AI Capabilities
+
+### `GET /ai-capabilities`
+
+Get AI capabilities status.
+
+**Handler:** `Gutenberg_Sidebar::handle_get_ai_capabilities()`
+
+**Permission:** `check_permissions`
+
+---
+
+## Research
+
+### `POST /search`
+
+Search the web (Brave Search).
+
+**Handler:** `Controller_Chat::handle_search()`
+
+**Permission:** `check_permissions`
+
+**Rate Limit:** 20 requests/minute
+
+---
+
+### `POST /fetch-content`
+
+Fetch web page content.
+
+**Handler:** `Controller_Chat::handle_fetch_content()`
+
+**Permission:** `check_permissions`
+
+**Rate Limit:** 10 requests/minute
+
+---
+
+### `POST /research-summary`
+
+Generate research summary.
+
+**Handler:** `Controller_Chat::handle_research_summary()`
+
+**Permission:** `check_permissions`
+
+---
+
+## MEMANTO (Memory)
+
+### `GET /memanto/status`
+
+Get MEMANTO service status.
+
+**Handler:** `Gutenberg_Sidebar::handle_memanto_status()`
+
+**Permission:** `check_permissions`
+
+---
+
+### `GET /memanto/recall`
+
+Recall recent memories for a post.
+
+**Handler:** `Gutenberg_Sidebar::handle_memanto_recall()`
+
+**Permission:** `check_permissions`
+
+---
+
+### `GET /memanto/restore`
+
+Restore session for cross-session continuity.
+
+**Handler:** `Gutenberg_Sidebar::handle_memanto_restore()`
+
+**Permission:** `check_permissions`
+
+---
+
+### `GET /memanto/preferences`
+
+Get user preferences for new post carry-over.
+
+**Handler:** `Gutenberg_Sidebar::handle_memanto_preferences()`
+
+**Permission:** `check_permissions`
+
+---
+
+## User Preferences
+
+### `GET /user-preferences`
+
+Get user preferences (public — no auth required).
+
+**Handler:** `Gutenberg_Sidebar::handle_get_user_preferences()`
+
+**Permission:** `__return_true` (public)
+
+---
+
+### `POST /user-preferences`
+
+Save user preferences.
+
+**Handler:** `Gutenberg_Sidebar::handle_save_user_preferences()`
+
+**Permission:** `check_permissions`
+
+---
+
+## Migration
+
+### `POST /migrate-chat-history/(?P<post_id>\d+)`
+
+Migrate legacy post meta chat history to conversations table.
+
+**Handler:** `Gutenberg_Sidebar::handle_migrate_chat_history()`
+
+**Permission:** `check_permissions` + post edit
+
+---
+
+## Error Codes
+
+| Code | HTTP Status | Description |
+|------|-------------|-------------|
+| `forbidden` | 403 | User lacks permission for this action |
+| `invalid_post` | 400 | Invalid or missing post ID |
+| `rate_limit_exceeded` | 429 | Too many requests |
+| `missing_tab_id` | 400 | Session lock requires tab_id |
+| Various WP_Error codes | varies | Provider-specific errors |
+
+---
+
+## Response Format
+
+All responses are JSON. Successful responses:
+
+```json
+{
+  "status": "success",
+  "data": { ... }
+}
+```
+
+Or directly the resource data:
+
+```json
+{
+  "key": "value"
+}
+```
+
+Error responses:
+
+```json
+{
+  "code": "error_code",
+  "message": "Human-readable message",
+  "data": { "status": 400 }
+}
+```