conductor(tracks): Add discussion_hub_panel_reorganization track

This track addresses the fragmented implementation of Session Context Snapshots
and Discussion Takes & Timeline Branching tracks (2026-03-11) which were
marked complete but the UI panel layout was not properly reorganized.

New track structure:
- Phase 1: Remove ui_summary_only, rename Context Hub to Project Settings
- Phase 2: Merge Session Hub into Discussion Hub (4 tabs)
- Phase 3: Context Composition tab (per-discussion file filter)
- Phase 4: DAW-style Takes timeline integration
- Phase 5: Final integration and cleanup

Also archives the two botched tracks and updates tracks.md.

conductor/tracks.md

@@ -1,4 +1,4 @@
-# Project Tracks
+# Project Tracks
 
 This file tracks all major tracks for the project. Each track has its own detailed plan in its respective folder.
 
@@ -67,14 +67,18 @@ This file tracks all major tracks for the project. Each track has its own detail
    *Link: [./tracks/presets_ai_settings_ux_20260311/](./tracks/presets_ai_settings_ux_20260311/)*
    *Goal: Improve the layout, scaling, and control ergonomics of the Preset windows (Personas, Prompts, Tools) and AI Settings panel. Includes dual-control sliders and categorized tool management.*
 
-8. [x] **Track: Session Context Snapshots & Visibility**
+8. [x] ~~**Track: Session Context Snapshots & Visibility**~~ (Archived 2026-03-22 - Replaced by discussion_hub_panel_reorganization)
    *Link: [./tracks/session_context_snapshots_20260311/](./tracks/session_context_snapshots_20260311/)*
    *Goal: Session-scoped context management, saving Context Presets, MMA assignment, and agent-focused session filtering in the UI.*
 
-9. [x] **Track: Discussion Takes & Timeline Branching**
+9. [x] ~~**Track: Discussion Takes & Timeline Branching**~~ (Archived 2026-03-22 - Replaced by discussion_hub_panel_reorganization)
    *Link: [./tracks/discussion_takes_branching_20260311/](./tracks/discussion_takes_branching_20260311/)*
    *Goal: Non-linear discussion timelines via tabbed "takes", message branching, and synthesis generation workflows.*
 
+12. [ ] **Track: Discussion Hub Panel Reorganization**
+    *Link: [./tracks/discussion_hub_panel_reorganization_20260322/](./tracks/discussion_hub_panel_reorganization_20260322/)*
+    *Goal: Properly merge Session Hub into Discussion Hub (4 tabs: Discussion | Context Composition | Snapshot | Takes), establish Files & Media as project-level inventory, deprecate ui_summary_only, implement Context Composition and DAW-style Takes.*
+
 10. [ ] **Track: Undo/Redo History Support**
     *Link: [./tracks/undo_redo_history_20260311/](./tracks/undo_redo_history_20260311/)*
     *Goal: Robust, non-provider based undo/redo for text inputs, UI controls, discussion mutations, and context management. Includes hotkey support and a history list view.*

conductor/tracks/discussion_hub_panel_reorganization_20260322/metadata.json

@@ -0,0 +1,22 @@
+{
+  "name": "discussion_hub_panel_reorganization",
+  "created": "2026-03-22",
+  "status": "in_progress",
+  "priority": "high",
+  "affected_files": [
+    "src/gui_2.py",
+    "src/models.py",
+    "src/project_manager.py",
+    "tests/test_gui_context_presets.py",
+    "tests/test_discussion_takes.py"
+  ],
+  "replaces": [
+    "session_context_snapshots_20260311",
+    "discussion_takes_branching_20260311"
+  ],
+  "related_tracks": [
+    "aggregation_smarter_summaries (future)",
+    "system_context_exposure (future)"
+  ],
+  "notes": "These earlier tracks were marked complete but the UI panel reorganization was not properly implemented. This track consolidates and properly executes the intended UX."
+}

conductor/tracks/discussion_hub_panel_reorganization_20260322/plan.md

@@ -0,0 +1,55 @@
+# Implementation Plan: Discussion Hub Panel Reorganization
+
+## Phase 1: Cleanup & Project Settings Rename
+Focus: Remove redundant ui_summary_only, rename Context Hub, establish project-level vs discussion-level separation
+
+- [ ] Task: Audit current ui_summary_only usages and document behavior to deprecate
+- [ ] Task: Remove ui_summary_only checkbox from _render_projects_panel (gui_2.py)
+- [ ] Task: Rename Context Hub to "Project Settings" in _gui_func tab bar
+- [ ] Task: Remove Context Presets tab from Project Settings (Context Hub)
+- [ ] Task: Update references in show_windows dict and any help text
+- [ ] Task: Write tests verifying ui_summary_only removal doesn't break existing functionality
+- [ ] Task: Conductor - User Manual Verification 'Phase 1: Cleanup & Project Settings Rename'
+
+## Phase 2: Merge Session Hub into Discussion Hub
+Focus: Move Session Hub tabs into Discussion Hub, eliminate separate Session Hub window
+
+- [ ] Task: Audit Session Hub (_render_session_hub) tab content
+- [ ] Task: Add Snapshot tab to Discussion Hub containing Aggregate MD + System Prompt preview
+- [ ] Task: Remove Session Hub window from _gui_func
+- [ ] Task: Add Discussion Hub tab bar structure (Discussion | Context Composition | Snapshot | Takes)
+- [ ] Task: Write tests for new tab structure rendering
+- [ ] Task: Conductor - User Manual Verification 'Phase 2: Merge Session Hub into Discussion Hub'
+
+## Phase 3: Context Composition Tab
+Focus: Per-discussion file filter with save/load preset functionality
+
+- [ ] Task: Write tests for Context Composition state management
+- [ ] Task: Create _render_context_composition_panel method
+- [ ] Task: Implement file/screenshot selection display (filtered from Files & Media)
+- [ ] Task: Implement per-file flags display (Auto-Aggregate, Force Full)
+- [ ] Task: Implement Save as Preset / Load Preset buttons
+- [ ] Task: Connect Context Presets storage to this panel
+- [ ] Task: Update Persona editor to reference Context Composition presets
+- [ ] Task: Write tests for Context Composition preset save/load
+- [ ] Task: Conductor - User Manual Verification 'Phase 3: Context Composition Tab'
+
+## Phase 4: Takes Timeline Integration
+Focus: DAW-style branching with proper visual timeline and synthesis
+
+- [ ] Task: Audit existing takes data structure and synthesis_formatter
+- [ ] Task: Enhance takes data model with parent_entry and parent_take tracking
+- [ ] Task: Implement Branch from Entry action in discussion history
+- [ ] Task: Implement visual timeline showing take divergence
+- [ ] Task: Integrate synthesis panel into Takes tab
+- [ ] Task: Implement take selection for synthesis
+- [ ] Task: Write tests for take branching and synthesis
+- [ ] Task: Conductor - User Manual Verification 'Phase 4: Takes Timeline Integration'
+
+## Phase 5: Final Integration & Cleanup
+Focus: Ensure all panels work together, remove dead code
+
+- [ ] Task: Run full test suite to verify no regressions
+- [ ] Task: Remove dead code from ui_summary_only references
+- [ ] Task: Update conductor/tracks.md to mark old session_context_snapshots and discussion_takes_branching as archived/replaced
+- [ ] Task: Conductor - User Manual Verification 'Phase 5: Final Integration & Cleanup'

conductor/tracks/discussion_hub_panel_reorganization_20260322/spec.md

@@ -0,0 +1,137 @@
+# Specification: Discussion Hub Panel Reorganization
+
+## 1. Overview
+
+This track addresses the fragmented implementation of Session Context Snapshots and Discussion Takes & Timeline Branching tracks (2026-03-11). Those tracks were marked complete but the UI panel layout was not properly reorganized.
+
+**Goal:** Create a coherent Discussion Hub that absorbs Session Hub functionality, establishes Files & Media as project-level file inventory, and properly implements Context Composition and DAW-style Takes branching.
+
+## 2. Current State Audit (as of 2026-03-22)
+
+### Already Implemented (DO NOT re-implement)
+- `ui_summary_only` checkbox in Projects panel
+- Session Hub as separate window with tabs: Aggregate MD | System Prompt
+- Context Hub with tabs: Projects | Paths | Context Presets
+- Context Presets save/load mechanism in project TOML
+- `_render_synthesis_panel()` method (gui_2.py:2612-2643) - basic synthesis UI
+- Takes data structure in `project['discussion']['discussions']`
+- Per-file `Auto-Aggregate` and `Force Full` flags in Files & Media
+
+### Gaps to Fill (This Track's Scope)
+1. `ui_summary_only` is redundant with per-file flags - deprecate it
+2. Context Hub renamed to "Project Settings" (remove Context Presets tab)
+3. Session Hub merged into Discussion Hub as tabs
+4. Files & Media stays separate as project-level inventory
+5. Context Composition tab in Discussion Hub for per-discussion filter
+6. Context Presets accessible via Context Composition (save/load filters)
+7. DAW-style Takes timeline properly integrated into Discussion Hub
+8. Synthesis properly integrated with Take selection
+
+## 3. Panel Layout Target
+
+| Panel | Location | Purpose |
+|-------|----------|---------|
+| **AI Settings** | Separate dockable | Provider, model, system prompts, tool presets, bias profiles |
+| **Files & Media** | Separate dockable | Project-level file inventory (addressable files) |
+| **Project Settings** | Context Hub → rename | Git dir, paths, project list (NO context stuff) |
+| **Discussion Hub** | Main hub | All discussion-related UI (tabs below) |
+| **MMA Dashboard** | Separate dockable | Multi-agent orchestration |
+| **Operations Hub** | Separate dockable | Tool calls, comms history, external tools |
+| **Diagnostics** | Separate dockable | Telemetry, logs |
+
+**Discussion Hub Tabs:**
+1. **Discussion** - Main conversation view (current implementation)
+2. **Context Composition** - File/screenshot filter + presets (NEW)
+3. **Snapshot** - Aggregate MD + System Prompt preview (moved from Session Hub)
+4. **Takes** - DAW-style timeline branching + synthesis (integrated, not separate panel)
+
+## 4. Functional Requirements
+
+### 4.1 Deprecate ui_summary_only
+- Remove `ui_summary_only` checkbox from Projects panel
+- Per-file flags (`Auto-Aggregate`, `Force Full`) are the intended mechanism
+- Document migration path for users
+
+### 4.2 Rename Context Hub → Project Settings
+- Context Hub tab bar: Projects | Paths
+- Remove "Context Presets" tab
+- All context-related functionality moves to Discussion Hub → Context Composition
+
+### 4.3 Merge Session Hub into Discussion Hub
+- Session Hub window eliminated
+- Its content becomes tabs in Discussion Hub:
+  - **Snapshot tab**: Aggregate MD preview, System Prompt preview, "Copy" buttons
+  - These were previously in Session Hub
+
+### 4.4 Context Composition Tab (NEW)
+- Shows currently selected files/screenshots for THIS discussion
+- Per-file flags: Auto-Aggregate, Force Full
+- **"Save as Preset"** / **"Load Preset"** buttons
+- Dropdown to select from saved presets
+- Relationship to Files & Media:
+  - Files & Media = the inventory (project-level)
+  - Context Composition = selected filter for current discussion
+
+### 4.5 Takes Timeline (DAW-Style)
+- **New Take**: Start fresh discussion thread
+- **Branch Take**: Fork from any discussion entry
+- **Switch Take**: Make a take the active discussion
+- **Rename/Delete Take**
+- All takes share the same Files & Media (not duplicated)
+- Non-destructive branching
+- Visual timeline showing divergence points
+
+### 4.6 Synthesis Integration
+- User selects 2+ takes via checkboxes
+- Click "Synthesize" button
+- AI generates "resolved" response considering all selected approaches
+- Result appears as new take
+- Accessible from Discussion Hub → Takes tab
+
+## 5. Data Model Changes
+
+### 5.1 Discussion State Structure
+```python
+# Per discussion in project['discussion']['discussions']
+{
+    "name": str,
+    "history": [
+        {"role": "user"|"assistant", "content": str, "ts": str, "files_injected": [...]}
+    ],
+    "parent_entry": Optional[int],  # index of parent message if branched
+    "parent_take": Optional[str],   # name of parent take if branched
+}
+```
+
+### 5.2 Context Preset Format
+```toml
+[context_preset.my_filter]
+files = ["path/to/file_a.py"]
+auto_aggregate = true
+force_full = false
+screenshots = ["path/to/shot1.png"]
+```
+
+## 6. Non-Functional Requirements
+- All changes must not break existing tests
+- New tests required for new functionality
+- Follow 1-space indentation Python code style
+- No comments unless explicitly requested
+
+## 7. Acceptance Criteria
+
+- [ ] `ui_summary_only` removed from Projects panel
+- [ ] Context Hub renamed to Project Settings
+- [ ] Session Hub window eliminated
+- [ ] Discussion Hub has 4 tabs: Discussion, Context Composition, Snapshot, Takes
+- [ ] Context Composition allows save/load of filter presets
+- [ ] Takes can be branched from any entry
+- [ ] Takes timeline shows divergence visually
+- [ ] Synthesis works with 2+ selected takes
+- [ ] All existing tests still pass
+- [ ] New tests cover new functionality
+
+## 8. Out of Scope
+- Aggregation improvements (sub-agent summarization, hash-based caching) - separate future track
+- System prompt exposure (`_SYSTEM_PROMPT` in ai_client.py) - separate future track
+- Session sophistication (Session as container for multiple discussions) - deferred