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/character_views.py

@@ -456,6 +456,14 @@ def list_characters():
             char_id = character.get('character_id')
             character['sessions'] = sessions_by_character.get(char_id, [])
 
+        # Fetch usage info for daily turn limits
+        usage_info = {}
+        try:
+            usage_response = api_client.get("/api/v1/usage")
+            usage_info = usage_response.get('result', {})
+        except (APIError, APINotFoundError) as e:
+            logger.debug("Could not fetch usage info", error=str(e))
+
         logger.info(
             "Characters listed",
             user_id=user.get('id'),
@@ -468,18 +476,46 @@ def list_characters():
             characters=characters,
             current_tier=current_tier,
             max_characters=max_characters,
-            can_create=can_create
+            can_create=can_create,
+            # 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 APITimeoutError:
         logger.error("API timeout while listing characters", user_id=user.get('id'))
         flash('Request timed out. Please try again.', 'error')
-        return render_template('character/list.html', characters=[], can_create=False)
+        return render_template(
+            'character/list.html',
+            characters=[],
+            can_create=False,
+            current_tier='free',
+            max_characters=1,
+            remaining=0,
+            daily_limit=0,
+            is_limited=False,
+            is_unlimited=False,
+            reset_time=''
+        )
 
     except APIError as e:
         logger.error("Failed to list characters", user_id=user.get('id'), error=str(e))
         flash('An error occurred while loading your characters.', 'error')
-        return render_template('character/list.html', characters=[], can_create=False)
+        return render_template(
+            'character/list.html',
+            characters=[],
+            can_create=False,
+            current_tier='free',
+            max_characters=1,
+            remaining=0,
+            daily_limit=0,
+            is_limited=False,
+            is_unlimited=False,
+            reset_time=''
+        )
 
 
 @character_bp.route('/<character_id>')
@@ -613,6 +649,58 @@ def create_session(character_id: str):
         return redirect(url_for('character_views.list_characters'))
 
 
+@character_bp.route('/sessions/<session_id>/delete', methods=['DELETE'])
+@require_auth_web
+def delete_session(session_id: str):
+    """
+    Delete a game session via HTMX.
+
+    This permanently removes the session from the database.
+    Returns a response that triggers page refresh to update UI properly
+    (handles "Continue Playing" button visibility).
+
+    Args:
+        session_id: ID of the session to delete
+    """
+    from flask import make_response
+
+    user = get_current_user()
+    api_client = get_api_client()
+
+    try:
+        api_client.delete(f"/api/v1/sessions/{session_id}")
+
+        logger.info(
+            "Session deleted via web UI",
+            user_id=user.get('id'),
+            session_id=session_id
+        )
+
+        # Return empty response with HX-Refresh to reload the page
+        # This ensures "Continue Playing" button visibility is correct
+        response = make_response('', 200)
+        response.headers['HX-Refresh'] = 'true'
+        return response
+
+    except APINotFoundError:
+        logger.warning(
+            "Session not found for deletion",
+            user_id=user.get('id'),
+            session_id=session_id
+        )
+        # Return error message that HTMX can display
+        return '<span class="error-message">Session not found</span>', 404
+
+    except APIError as e:
+        logger.error(
+            "Failed to delete session",
+            user_id=user.get('id'),
+            session_id=session_id,
+            error=str(e)
+        )
+        return '<span class="error-message">Failed to delete session</span>', 500
+
+
 @character_bp.route('/<character_id>/skills')
 @require_auth_web
 def view_skills(character_id: str):

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))