feat(web): add navigation menu bar for logged-in users

- Add horizontal nav menu with 7 items: Profile, Characters, Sessions,
  Mechanics, Leaderboard, Settings, Help
- Implement responsive hamburger menu for mobile (≤768px)
- Create pages blueprint with stub routes for new pages
- Add "Coming Soon" styled stub templates with icons
- Include active state highlighting for current page

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

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

public_web/app/__init__.py

@@ -57,10 +57,12 @@ def create_app():
     from .views.auth_views import auth_bp
     from .views.character_views import character_bp
     from .views.game_views import game_bp
+    from .views.pages import pages_bp
 
     app.register_blueprint(auth_bp)
     app.register_blueprint(character_bp)
     app.register_blueprint(game_bp)
+    app.register_blueprint(pages_bp)
 
     # Register Jinja filters
     def format_timestamp(iso_string: str) -> str:
@@ -107,6 +109,6 @@ def create_app():
         logger.error("internal_server_error", error=str(error))
         return render_template('errors/500.html'), 500
 
-    logger.info("flask_app_created", blueprints=["auth", "character", "game"])
+    logger.info("flask_app_created", blueprints=["auth", "character", "game", "pages"])
 
     return app

public_web/app/views/pages.py

@@ -0,0 +1,96 @@
+"""
+Pages Views Blueprint
+
+This module provides web UI routes for static/stub pages:
+- Profile page
+- Sessions page
+- Mechanics page
+- Leaderboard page
+- Settings page
+- Help page
+
+These are currently stub pages that will be implemented in future phases.
+"""
+
+from flask import Blueprint, render_template
+from app.utils.auth import require_auth_web
+from app.utils.logging import get_logger
+
+
+# Initialize logger
+logger = get_logger(__file__)
+
+# Create blueprint
+pages_bp = Blueprint('pages', __name__)
+
+
+@pages_bp.route('/profile')
+@require_auth_web
+def profile():
+    """
+    Display player profile page.
+
+    Currently a stub - will show player stats, achievements, etc.
+    """
+    logger.info("Accessing profile page")
+    return render_template('pages/profile.html')
+
+
+@pages_bp.route('/sessions')
+@require_auth_web
+def sessions():
+    """
+    Display active game sessions page.
+
+    Currently a stub - will show list of active/past sessions.
+    """
+    logger.info("Accessing sessions page")
+    return render_template('pages/sessions.html')
+
+
+@pages_bp.route('/mechanics')
+@require_auth_web
+def mechanics():
+    """
+    Display game mechanics reference page.
+
+    Currently a stub - will explain combat, skills, items, etc.
+    """
+    logger.info("Accessing mechanics page")
+    return render_template('pages/mechanics.html')
+
+
+@pages_bp.route('/leaderboard')
+@require_auth_web
+def leaderboard():
+    """
+    Display leaderboard page.
+
+    Currently a stub - will show top players, achievements, etc.
+    """
+    logger.info("Accessing leaderboard page")
+    return render_template('pages/leaderboard.html')
+
+
+@pages_bp.route('/settings')
+@require_auth_web
+def settings():
+    """
+    Display user settings page.
+
+    Currently a stub - will allow account settings, preferences, etc.
+    """
+    logger.info("Accessing settings page")
+    return render_template('pages/settings.html')
+
+
+@pages_bp.route('/help')
+@require_auth_web
+def help_page():
+    """
+    Display help/guide page.
+
+    Currently a stub - will provide tutorials, FAQs, support info.
+    """
+    logger.info("Accessing help page")
+    return render_template('pages/help.html')