feat: implement Pages as Spaces Phase 1

- Add PageConfig model with feature flags (calendar, market)
- Auto-create PageConfig on Ghost page sync
- Add create_page() for Ghost /pages/ API endpoint
- Add /new-page/ route for creating pages
- Add ?type=pages blog filter with Posts|Pages tab toggle
- Add list_pages() to DBClient with PageConfig eager loading
- Add PUT /<slug>/admin/features/ route for feature toggles
- Add feature badges (calendar, market) on page cards
- Add features panel to page admin dashboard
- Update shared_lib submodule with PageConfig model

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

bp/post/admin/routes.py

@@ -22,17 +22,91 @@ def register():
   @require_admin
   async def admin(slug: str):
     from suma_browser.app.utils.htmx import is_htmx_request
+    from models.page_config import PageConfig
+    from sqlalchemy import select as sa_select
+
+    # Load features for page admin
+    post = (g.post_data or {}).get("post", {})
+    features = {}
+    if post.get("is_page"):
+        pc = (await g.s.execute(
+            sa_select(PageConfig).where(PageConfig.post_id == post["id"])
+        )).scalar_one_or_none()
+        if pc:
+            features = pc.features or {}
+
+    ctx = {"features": features}
 
     # Determine which template to use based on request type
     if not is_htmx_request():
         # Normal browser request: full page with layout
-        html = await render_template("_types/post/admin/index.html")
+        html = await render_template("_types/post/admin/index.html", **ctx)
     else:
         # HTMX request: main panel + OOB elements
-        html = await render_template("_types/post/admin/_oob_elements.html")
+        html = await render_template("_types/post/admin/_oob_elements.html", **ctx)
 
     return await make_response(html)
 
+  @bp.put("/features/")
+  @require_admin
+  async def update_features(slug: str):
+    """Update PageConfig.features for a page."""
+    from models.page_config import PageConfig
+    from models.ghost_content import Post
+    from sqlalchemy import select as sa_select
+    from quart import jsonify
+    import json
+
+    post = g.post_data.get("post")
+    if not post or not post.get("is_page"):
+        return jsonify({"error": "This is not a page."}), 400
+
+    post_id = post["id"]
+
+    # Load PageConfig
+    pc = (await g.s.execute(
+        sa_select(PageConfig).where(PageConfig.post_id == post_id)
+    )).scalar_one_or_none()
+    if pc is None:
+        return jsonify({"error": "PageConfig not found for this page."}), 404
+
+    # Parse request body
+    body = await request.get_json()
+    if body is None:
+        # Fall back to form data
+        form = await request.form
+        body = {}
+        for key in ("calendar", "market"):
+            val = form.get(key)
+            if val is not None:
+                body[key] = val in ("true", "1", "on")
+
+    if not isinstance(body, dict):
+        return jsonify({"error": "Expected JSON object with feature flags."}), 400
+
+    # Merge features
+    features = dict(pc.features or {})
+    for key, val in body.items():
+        if isinstance(val, bool):
+            features[key] = val
+        elif val in ("true", "1", "on"):
+            features[key] = True
+        elif val in ("false", "0", "off", None):
+            features[key] = False
+
+    pc.features = features
+    from sqlalchemy.orm.attributes import flag_modified
+    flag_modified(pc, "features")
+    await g.s.flush()
+
+    # Return updated features panel
+    html = await render_template(
+        "_types/post/admin/_features_panel.html",
+        features=features,
+        post=post,
+    )
+    return await make_response(html)
+
   @bp.get("/data/")
   @require_admin
   async def data(slug: str):