Phase 0+1: native post writes, Ghost no longer write-primary

- Final sync script with HTML verification + author→user migration
- Make ghost_id nullable on posts/authors/tags, add UUID/timestamp defaults
- Add user profile fields (bio, slug, profile_image, etc.) to User model
- New PostUser M2M table (replaces post_authors for new posts)
- PostWriter service: direct DB CRUD with Lexical rendering, optimistic
  locking, AP federation, tag upsert
- Rewrite create/edit/settings routes to use PostWriter (no Ghost API calls)
- Neuter Ghost webhooks (post/page/author/tag → 204 no-op)
- Disable Ghost startup sync

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

blog/bp/blog/routes.py

@@ -14,7 +14,6 @@ from quart import (
     url_for,
 )
 from .ghost_db import DBClient  # adjust import path
-from shared.db.session import get_session
 from .filters.qs import makeqs_factory, decode
 from .services.posts_data import posts_data
 from .services.pages_data import pages_data
@@ -47,33 +46,9 @@ def register(url_prefix, title):
 
     @blogs_bp.before_app_serving
     async def init():
-      from .ghost.ghost_sync import sync_all_content_from_ghost
-      from sqlalchemy import text
-      import logging
-      logger = logging.getLogger(__name__)
-
-      # Advisory lock prevents multiple Hypercorn workers from
-      # running the sync concurrently (which causes PK conflicts).
-      async with get_session() as s:
-        got_lock = await s.scalar(text("SELECT pg_try_advisory_lock(900001)"))
-        if not got_lock:
-            await s.rollback()  # clean up before returning connection to pool
-            return
-        try:
-            await sync_all_content_from_ghost(s)
-            await s.commit()
-        except Exception:
-            logger.exception("Ghost sync failed — will retry on next deploy")
-            try:
-                await s.rollback()
-            except Exception:
-                pass
-        finally:
-            try:
-                await s.execute(text("SELECT pg_advisory_unlock(900001)"))
-                await s.commit()
-            except Exception:
-                pass  # lock auto-releases when session closes
+      # Ghost startup sync disabled (Phase 1) — blog service owns content
+      # directly. The final_ghost_sync.py script was run before cutover.
+      pass
 
     @blogs_bp.before_request
     def route():
@@ -258,9 +233,8 @@ def register(url_prefix, title):
     @blogs_bp.post("/new/")
     @require_admin
     async def new_post_save():
-      from .ghost.ghost_posts import create_post
       from .ghost.lexical_validator import validate_lexical
-      from .ghost.ghost_sync import sync_single_post
+      from services.post_writer import create_post as writer_create
 
       form = await request.form
       title = form.get("title", "").strip() or "Untitled"
@@ -290,35 +264,24 @@ def register(url_prefix, title):
         html = await render_new_post_page(tctx)
         return await make_response(html, 400)
 
-      # Create in Ghost
-      ghost_post = await create_post(
+      # Create directly in db_blog
+      post = await writer_create(
+          g.s,
           title=title,
           lexical_json=lexical_raw,
           status=status,
+          user_id=g.user.id,
           feature_image=feature_image or None,
           custom_excerpt=custom_excerpt or None,
           feature_image_caption=feature_image_caption or None,
       )
-
-      # Sync to local DB
-      await sync_single_post(g.s, ghost_post["id"])
       await g.s.flush()
 
-      # Set user_id on the newly created post
-      from models.ghost_content import Post
-      from sqlalchemy import select
-      local_post = (await g.s.execute(
-          select(Post).where(Post.ghost_id == ghost_post["id"])
-      )).scalar_one_or_none()
-      if local_post and local_post.user_id is None:
-          local_post.user_id = g.user.id
-          await g.s.flush()
-
       # Clear blog listing cache
       await invalidate_tag_cache("blog")
 
-      # Redirect to the edit page (post is likely a draft, so public detail would 404)
-      return redirect(host_url(url_for("blog.post.admin.edit", slug=ghost_post["slug"])))
+      # Redirect to the edit page
+      return redirect(host_url(url_for("blog.post.admin.edit", slug=post.slug)))
 
 
     @blogs_bp.get("/new-page/")
@@ -340,9 +303,8 @@ def register(url_prefix, title):
     @blogs_bp.post("/new-page/")
     @require_admin
     async def new_page_save():
-      from .ghost.ghost_posts import create_page
       from .ghost.lexical_validator import validate_lexical
-      from .ghost.ghost_sync import sync_single_page
+      from services.post_writer import create_page as writer_create_page
 
       form = await request.form
       title = form.get("title", "").strip() or "Untitled"
@@ -374,35 +336,24 @@ def register(url_prefix, title):
         html = await render_new_post_page(tctx)
         return await make_response(html, 400)
 
-      # Create in Ghost (as page)
-      ghost_page = await create_page(
+      # Create directly in db_blog
+      page = await writer_create_page(
+          g.s,
           title=title,
           lexical_json=lexical_raw,
           status=status,
+          user_id=g.user.id,
           feature_image=feature_image or None,
           custom_excerpt=custom_excerpt or None,
           feature_image_caption=feature_image_caption or None,
       )
-
-      # Sync to local DB (uses pages endpoint)
-      await sync_single_page(g.s, ghost_page["id"])
       await g.s.flush()
 
-      # Set user_id on the newly created page
-      from models.ghost_content import Post
-      from sqlalchemy import select
-      local_post = (await g.s.execute(
-          select(Post).where(Post.ghost_id == ghost_page["id"])
-      )).scalar_one_or_none()
-      if local_post and local_post.user_id is None:
-          local_post.user_id = g.user.id
-          await g.s.flush()
-
       # Clear blog listing cache
       await invalidate_tag_cache("blog")
 
       # Redirect to the page admin
-      return redirect(host_url(url_for("blog.post.admin.edit", slug=ghost_page["slug"])))
+      return redirect(host_url(url_for("blog.post.admin.edit", slug=page.slug)))
 
 
     @blogs_bp.get("/drafts/")