feat: sistem de linkuri publice pentru proprietăți

Expune fluxul de rezervare anonimă printr-un link public partajabil
(/book/<slug>), cu calendar public, cod QR și proprietate demo publică.

Backend:
- slug + list_on_landing pe Property; utilitar slugify (diacritice RO,
  cuvinte rezervate, ban all-digit) + migrare idempotentă raw-DDL rulată
  din entrypoint; SQLite WAL + busy_timeout
- GET /public/properties/{slug_or_id}(+/spaces): rezolvare slug/ID, 404 uniform
- GET /public/spaces/{id}/busy: doar {start_time,end_time} (fără PII),
  pending+approved, tz-aware/interval>60z → 422, orfan/privat → 404
- availability: scrub user_name/title (fix scurgere PII)
- POST /public/bookings: overlap pending+approved, cap 5/email/spațiu/zi,
  rate-limit per-IP, suprimare notificări+email pe demo, email confirmare guest
- PATCH slug (409 duplicat / 422 format / 403 non-manager); guest_email EmailStr
- email guest la aprobare/respingere cu cod #RB-<id>
- teste noi: test_public.py + test_migrate_slug.py (33 teste)

Frontend:
- rută /book/:slug; PublicBooking rescris cu calendar grid manual
  (PublicCalendar + GuestBookingForm), 30min, 08-20, mobil day-view, RO
- card „Link public" în PropertyDetail: copy, edit slug, QR pe URL-ul cu ID
- secțiune proprietăți publice + CTA pe Landing; buton copy în Properties

Gate aprobat (U1-U3, G1 grid manual, G2 list_on_landing); G3-G5 în TODOS.md.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

backend/migrate_add_property_slug.py

@@ -0,0 +1,89 @@
+"""Migration script to add public-booking-link slug support to properties.
+
+Idempotent (safe to run multiple times):
+- Adds `slug` (VARCHAR, nullable) and `list_on_landing` (BOOLEAN NOT NULL
+  DEFAULT 0) columns to `properties` if missing.
+- Creates a UNIQUE INDEX on `slug` if missing.
+- Backfills NULL slugs deterministically from each property's name.
+"""
+import sys
+import os
+
+# Add backend to path
+sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
+
+from sqlalchemy import inspect, text
+
+from app.core.slug import generate_unique_slug
+from app.db.session import SessionLocal, engine
+from app.models.property import Property
+
+SLUG_INDEX_NAME = "ix_properties_slug_unique"
+
+
+def migrate() -> None:
+    """Run migration to add slug + list_on_landing support to properties."""
+    inspector = inspect(engine)
+    columns = [col["name"] for col in inspector.get_columns("properties")]
+
+    print("Starting property slug migration...")
+
+    with engine.connect() as conn:
+        if "slug" not in columns:
+            print("1. Adding slug column to properties...")
+            conn.execute(text("ALTER TABLE properties ADD COLUMN slug VARCHAR"))
+            conn.commit()
+            print("   Column added.")
+        else:
+            print("1. slug column already exists.")
+
+        if "list_on_landing" not in columns:
+            print("2. Adding list_on_landing column to properties...")
+            conn.execute(
+                text("ALTER TABLE properties ADD COLUMN list_on_landing BOOLEAN DEFAULT 0 NOT NULL")
+            )
+            conn.commit()
+            print("   Column added.")
+        else:
+            print("2. list_on_landing column already exists.")
+
+    # Recompute indexes after potentially adding the slug column.
+    inspector = inspect(engine)
+    index_names = {ix["name"] for ix in inspector.get_indexes("properties")}
+    if SLUG_INDEX_NAME not in index_names:
+        print("3. Creating unique index on slug...")
+        with engine.connect() as conn:
+            conn.execute(
+                text(f"CREATE UNIQUE INDEX {SLUG_INDEX_NAME} ON properties (slug)")
+            )
+            conn.commit()
+        print("   Index created.")
+    else:
+        print("3. Unique index on slug already exists.")
+
+    # Backfill: deterministic unique slug for every property missing one.
+    print("4. Backfilling missing slugs...")
+    db = SessionLocal()
+    try:
+        properties_without_slug = (
+            db.query(Property)
+            .filter(Property.slug.is_(None))
+            .order_by(Property.id)
+            .all()
+        )
+        for prop in properties_without_slug:
+            prop.slug = generate_unique_slug(db, prop.name, exclude_id=prop.id)
+            db.flush()
+        db.commit()
+        print(f"   Backfilled {len(properties_without_slug)} propert(y/ies).")
+    except Exception:
+        db.rollback()
+        raise
+    finally:
+        db.close()
+
+    print("Migration completed successfully!")
+
+
+if __name__ == "__main__":
+    migrate()