Implement smart notification system with intelligent content analysis

Major improvements to notification handling:
- Replace blanket skip_notifications with content source analysis
- Immediate notifications for external mentions, DMs, and posts from others
- Smart sound selection based on content type (mention/DM/timeline_update)
- Remove focus-based auto-refresh blocking for seamless background updates
- Fix notifications timeline AttributeError from removed skip_notifications
- Track user actions to prevent sound spam from own expected content
- Context-aware suppression only for user's own posts, not external content

User experience improvements:
- Never miss external mentions or DMs due to timing issues
- Auto-refresh works regardless of timeline focus
- Appropriate sounds play immediately for genuine external notifications
- No redundant sounds from user's own post actions

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

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

CLAUDE.md

@@ -7,6 +7,57 @@ Bifrost is a fully accessible fediverse client built with PySide6, designed spec
 - Check for any changes in git project before doing anything else. Make sure the latest changes have been pulled
 - See what has changed, use git commands and examine the code to make sure you are up to date with the latest code
 
+## Smart Notification System
+
+Bifrost includes an intelligent notification system that distinguishes between user's own content and external content from others.
+
+### Core Features
+1. **Content Source Analysis**: Determines if new content is from current user or external users
+2. **Immediate External Notifications**: Never suppresses sounds for genuine mentions, DMs, or posts from others
+3. **Smart Sound Selection**: Plays appropriate sounds (mention, direct_message, timeline_update) based on content type
+4. **Context-Aware Suppression**: Only suppresses sounds from user's own expected content
+5. **No Timeline Switch Delays**: Auto-refresh works immediately without waiting for focus loss
+
+### Implementation Details
+
+#### Timeline Notification Logic (timeline_view.py:541-638)
+```python
+# Check if notifications should be suppressed (initial load, recent timeline switch)
+suppress_all = self.should_suppress_notifications()
+
+if not suppress_all:
+    # Analyze new content to separate external content from user's own
+    for post in new_posts:
+        if self.is_content_from_current_user(post):
+            user_content_detected = True
+        else:
+            external_content_detected = True
+    
+    # Play sounds and notifications for external content only
+    if external_content_detected:
+        # Check for mentions, DMs, then fallback to timeline_update
+```
+
+#### User Action Tracking (timeline_view.py:155-175)
+```python
+def track_user_action(self, action_type: str, expected_content_hint: str = None):
+    """Track user actions to avoid sound spam from expected results"""
+    action_info = {
+        'type': action_type,
+        'timestamp': time.time(),
+        'hint': expected_content_hint
+    }
+    self.recent_user_actions.append(action_info)
+```
+
+### Migration from Old System
+
+**Removed:** `skip_notifications` blanket suppression flag  
+**Replaced with:** `should_suppress_notifications()` method that checks:
+- Initial load state
+- Timeline switch timing (3s delay for most timelines, 1s for notifications)
+- But allows immediate external content notifications
+
 ## Duplicate Code Prevention Guidelines
 
 ### Critical Areas Requiring Attention
@@ -14,7 +65,7 @@ Bifrost is a fully accessible fediverse client built with PySide6, designed spec
 2. **UI Event Handlers**: Avoid circular event chains (A triggers B which triggers A)
 3. **Timeline Operations**: Coordinate refresh calls and state changes to prevent conflicts
 4. **Lifecycle Events**: Ensure shutdown, close, and quit events don't overlap
-4. **Design**: Ensure  single point of truth is used as much as possible through out the code. This means functionality should not be duplicated across files.
+5. **Design**: Ensure single point of truth is used as much as possible throughout the code
 
 ### Required Patterns for Event-Heavy Operations
 
@@ -690,4 +741,26 @@ content_text.setTextInteractionFlags(Qt.TextSelectableByKeyboard | Qt.TextSelect
 - Content tab: Full post details in accessible text widget
 - Interaction tabs: Who favorited/boosted in accessible lists
 
+## Recent Major Changes (July 2025)
+
+### Smart Notification System Implementation
+**Problem Solved:** The old `skip_notifications` system suppressed ALL sounds for 1-3 seconds after user actions, causing users to miss important external content (mentions, DMs) that arrived during post-action refreshes.
+
+**Solution Implemented:**
+1. **Replaced blanket suppression** with content source analysis
+2. **Immediate external notifications** - never suppress sounds for genuine mentions/DMs from others
+3. **Context-aware sound selection** - different sounds for mentions vs DMs vs timeline updates
+4. **Removed focus-based auto-refresh blocking** - auto-refresh now works regardless of timeline focus
+5. **Fixed notifications timeline** - resolved AttributeError from removed `skip_notifications` references
+
+**Key Files Modified:**
+- `src/widgets/timeline_view.py`: Core notification logic, content analysis, auto-refresh improvements
+- `src/main_window.py`: Updated notification suppression checks
+
+**User Experience Impact:**
+- Users now get immediate audio feedback for external content even during their own actions
+- Auto-refresh works seamlessly without waiting for focus loss
+- Notifications timeline properly loads without errors
+- No more missed mentions or DMs due to timing issues
+
 This document serves as the comprehensive development guide for Bifrost, ensuring all accessibility, functionality, and architectural decisions are preserved and can be referenced throughout development.