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/services/slots.py

@@ -0,0 +1,117 @@
+
+from __future__ import annotations
+from datetime import time
+from typing import Sequence
+
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from models.calendars import CalendarSlot
+
+class SlotError(ValueError):
+    pass
+
+def _b(v):
+    if isinstance(v, bool):
+        return v
+    s = str(v).lower()
+    return s in {"1","true","t","yes","y","on"}
+
+async def list_slots(sess: AsyncSession, calendar_id: int) -> Sequence[CalendarSlot]:
+    res = await sess.execute(
+        select(CalendarSlot)
+        .where(CalendarSlot.calendar_id == calendar_id, CalendarSlot.deleted_at.is_(None))
+        .order_by(CalendarSlot.time_start.asc(), CalendarSlot.id.asc())
+    )
+    return res.scalars().all()
+
+async def create_slot(sess: AsyncSession, calendar_id: int, *, name: str, description: str | None,
+                      days: dict, time_start: time, time_end: time, cost: float | None):
+    if not name:
+        raise SlotError("name is required")
+    if not time_start or not time_end or time_end <= time_start:
+        raise SlotError("time range invalid")
+    slot = CalendarSlot(
+        calendar_id=calendar_id,
+        name=name,
+        description=(description or None),
+        mon=_b(days.get("mon")), tue=_b(days.get("tue")), wed=_b(days.get("wed")),
+        thu=_b(days.get("thu")), fri=_b(days.get("fri")), sat=_b(days.get("sat")), sun=_b(days.get("sun")),
+        time_start=time_start, time_end=time_end, cost=cost,
+    )
+    sess.add(slot)
+    await sess.flush()
+    return slot
+
+async def update_slot(
+    sess: AsyncSession,
+    slot_id: int,
+    *,
+    name: str | None = None,
+    description: str | None = None,
+    days: dict | None = None,
+    time_start: time | None = None,
+    time_end: time | None = None,
+    cost: float | None = None,
+    flexible: bool | None = None,   # NEW
+):
+    slot = await sess.get(CalendarSlot, slot_id)
+    if not slot or slot.deleted_at is not None:
+        raise SlotError("slot not found")
+
+    if name is not None:
+        slot.name = name
+
+    if description is not None:
+        slot.description = description or None
+
+    if days is not None:
+        slot.mon = _b(days.get("mon", slot.mon))
+        slot.tue = _b(days.get("tue", slot.tue))
+        slot.wed = _b(days.get("wed", slot.wed))
+        slot.thu = _b(days.get("thu", slot.thu))
+        slot.fri = _b(days.get("fri", slot.fri))
+        slot.sat = _b(days.get("sat", slot.sat))
+        slot.sun = _b(days.get("sun", slot.sun))
+
+    if time_start is not None:
+        slot.time_start = time_start
+    if time_end is not None:
+        slot.time_end = time_end
+
+    if (time_start or time_end) and slot.time_end <= slot.time_start:
+        raise SlotError("time range invalid")
+
+    if cost is not None:
+        slot.cost = cost
+
+    # NEW: update flexible flag only if explicitly provided
+    if flexible is not None:
+        slot.flexible = flexible
+
+    await sess.flush()
+    return slot
+
+async def soft_delete_slot(sess: AsyncSession, slot_id: int):
+    slot = await sess.get(CalendarSlot, slot_id)
+    if not slot or slot.deleted_at is not None:
+        return
+    from datetime import datetime, timezone
+    slot.deleted_at = datetime.now(timezone.utc)
+    await sess.flush()
+
+
+async def get_slot(sess: AsyncSession, slot_id: int) -> CalendarSlot | None:
+    return await sess.get(CalendarSlot, slot_id)
+
+async def update_slot_description(
+    sess: AsyncSession,
+    slot_id: int,
+    description: str | None,
+) -> CalendarSlot:
+    slot = await sess.get(CalendarSlot, slot_id)
+    if not slot:
+        raise SlotError("slot not found")
+    slot.description = description or None
+    await sess.flush()
+    return slot