feat: initialize events app with calendars, slots, tickets, and internal API

Extract events/calendar functionality into standalone microservice:
- app.py and events_api.py from apps/events/
- Calendar blueprints (calendars, calendar, calendar_entries, calendar_entry, day, slots, slot, ticket_types, ticket_type)
- Templates for all calendar/event views including admin
- Dockerfile (APP_MODULE=app:app, IMAGE=events)
- entrypoint.sh (no Alembic - migrations managed by blog app)
- Gitea CI workflow for build and deploy

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

bp/calendar/admin/routes.py

@@ -0,0 +1,76 @@
+from __future__ import annotations
+
+from quart import (
+    request, render_template, make_response, Blueprint, g
+)
+
+
+from suma_browser.app.authz import require_admin
+from suma_browser.app.redis_cacher import clear_cache
+
+
+
+
+def register():
+    bp = Blueprint("admin", __name__, url_prefix='/admin')
+    # ---------- Pages ----------
+    @bp.get("/")
+    @require_admin
+    async def admin(slug: str, calendar_slug: str):
+        from suma_browser.app.utils.htmx import is_htmx_request
+
+        # 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/calendar/admin/index.html")
+        else:
+            # HTMX request: main panel + OOB elements
+            html = await render_template("_types/calendar/admin/_oob_elements.html")
+
+        return await make_response(html)
+    
+
+    @bp.get("/description/")
+    @require_admin
+    async def calendar_description_edit(slug: str, calendar_slug: str):
+        # g.post and g.calendar should already be set by the parent calendar bp
+        html = await render_template(
+            "_types/calendar/admin/_description_edit.html",
+            post=g.post_data['post'],
+            calendar=g.calendar,
+        )
+        return await make_response(html)
+
+
+    @bp.post("/description/")
+    @require_admin
+    @clear_cache(tag="calendars", tag_scope="all")
+    async def calendar_description_save(slug: str, calendar_slug: str):
+        form = await request.form
+        description = (form.get("description") or "").strip() or None
+
+        # simple inline update, or call a service if you prefer
+        g.calendar.description = description
+        await g.s.flush()
+
+        html = await render_template(
+            "_types/calendar/admin/_description.html",
+            post=g.post_data['post'],
+            calendar=g.calendar,
+            oob=True
+        )
+        return await make_response(html)
+
+
+    @bp.get("/description/view/")
+    @require_admin
+    async def calendar_description_view(slug: str, calendar_slug: str):
+        # just render the display version without touching the DB (used by Cancel)
+        html = await render_template(
+            "_types/calendar/admin/_description.html",
+            post=g.post_data['post'],
+            calendar=g.calendar,
+        )
+        return await make_response(html)
+    
+    return bp