feat(api,web): tier-based session limits and daily turn usage display

Backend Changes:
- Add tier-based max_sessions config (free: 1, basic: 2, premium: 3, elite: 5)
- Add DELETE /api/v1/sessions/{id} endpoint for hard session deletion
- Cascade delete chat messages when session is deleted
- Add GET /api/v1/usage endpoint for daily turn limit info
- Replace hardcoded TIER_LIMITS with config-based ai_calls_per_day
- Handle unlimited (-1) tier in rate limiter service

Frontend Changes:
- Add inline session delete buttons with HTMX on character list
- Add usage_display.html component showing remaining daily turns
- Display usage indicator on character list and game play pages
- Page refresh after session deletion to update UI state

Documentation:
- Update API_REFERENCE.md with new endpoints and tier limits
- Update API_TESTING.md with session endpoint examples
- Update SESSION_MANAGEMENT.md with tier-based limits

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

public_web/app/views/game_views.py

@@ -201,6 +201,14 @@ def play_session(session_id: str):
         # Get user tier
         user_tier = _get_user_tier(client)
 
+        # Fetch usage info for daily turn limits
+        usage_info = {}
+        try:
+            usage_response = client.get("/api/v1/usage")
+            usage_info = usage_response.get('result', {})
+        except (APINotFoundError, APIError) as e:
+            logger.debug("could_not_fetch_usage_info", error=str(e))
+
         # Build session object for template
         session = {
             'session_id': session_id,
@@ -220,7 +228,13 @@ def play_session(session_id: str):
             npcs=npcs,
             discovered_locations=discovered_locations,
             actions=DEFAULT_ACTIONS,
-            user_tier=user_tier
+            user_tier=user_tier,
+            # Usage display variables
+            remaining=usage_info.get('remaining', 0),
+            daily_limit=usage_info.get('daily_limit', 0),
+            is_limited=usage_info.get('is_limited', False),
+            is_unlimited=usage_info.get('is_unlimited', False),
+            reset_time=usage_info.get('reset_time', '')
         )
 
     except APINotFoundError:
@@ -259,13 +273,27 @@ def character_panel(session_id: str):
         character = _build_character_from_api(char_data)
         user_tier = _get_user_tier(client)
 
+        # Fetch usage info for daily turn limits
+        usage_info = {}
+        try:
+            usage_response = client.get("/api/v1/usage")
+            usage_info = usage_response.get('result', {})
+        except (APINotFoundError, APIError) as e:
+            logger.debug("could_not_fetch_usage_info", error=str(e))
+
         return render_template(
             'game/partials/character_panel.html',
             session_id=session_id,
             character=character,
             location=location,
             actions=DEFAULT_ACTIONS,
-            user_tier=user_tier
+            user_tier=user_tier,
+            # Usage display variables
+            remaining=usage_info.get('remaining', 0),
+            daily_limit=usage_info.get('daily_limit', 0),
+            is_limited=usage_info.get('is_limited', False),
+            is_unlimited=usage_info.get('is_unlimited', False),
+            reset_time=usage_info.get('reset_time', '')
         )
     except APIError as e:
         logger.error("failed_to_refresh_character_panel", session_id=session_id, error=str(e))