fix: enhance workflow execute session selection with user interaction

- Add detailed session discovery logic with 3 cases (none, single, multiple)
- Implement AskUserQuestion for multiple active sessions
- Display rich session metadata (project name, task progress, completion %)
- Support flexible user input (session number, full ID, or partial ID)
- Maintain backward compatibility for single-session scenarios
- Improve user experience with clear confirmation messages

This minimal change addresses session conflict issues without complex
locking mechanisms, focusing on explicit user choice when ambiguity exists.

.claude/commands/workflow/execute.md

@@ -54,13 +54,89 @@ Orchestrates autonomous workflow execution through systematic task discovery, ag
 ### Phase 1: Discovery
 **Applies to**: Normal mode only (skipped in resume mode)
 
-**Process**:
-1. **Check Active Sessions**: Find sessions in `.workflow/active/` directory
-2. **Select Session**: If multiple found, prompt user selection
-3. **Load Session Metadata**: Read `workflow-session.json` ONLY (minimal context)
-4. **DO NOT read task JSONs yet** - defer until execution phase
+**Purpose**: Find and select active workflow session with user confirmation when multiple sessions exist
 
-**Resume Mode**: This phase is completely skipped when `--resume-session="session-id"` flag is provided.
+**Process**:
+
+#### Step 1.1: Count Active Sessions
+```bash
+bash(find .workflow/active/ -name "WFS-*" -type d 2>/dev/null | wc -l)
+```
+
+#### Step 1.2: Handle Session Selection
+
+**Case A: No Active Sessions (count = 0)**
+```
+ERROR: No active workflow sessions found
+SOLUTION: Run /workflow:plan "task description" to create a session
+```
+Stop execution and return error to user.
+
+**Case B: Single Active Session (count = 1)**
+```bash
+bash(find .workflow/active/ -name "WFS-*" -type d 2>/dev/null | head -1 | xargs basename)
+```
+Store as `sessionId` and continue to Phase 2 (no user interaction needed).
+
+**Case C: Multiple Active Sessions (count > 1)**
+
+1. **List sessions with rich metadata**:
+```bash
+bash(for dir in .workflow/active/WFS-*/; do
+  session=$(basename "$dir")
+  project=$(jq -r '.project // "Unknown"' "$dir/workflow-session.json" 2>/dev/null)
+  total=$(grep -c "^- \[" "$dir/TODO_LIST.md" 2>/dev/null || echo "0")
+  completed=$(grep -c "^- \[x\]" "$dir/TODO_LIST.md" 2>/dev/null || echo "0")
+
+  if [ "$total" -gt 0 ]; then
+    progress=$((completed * 100 / total))
+  else
+    progress=0
+  fi
+
+  echo "${session} | ${project} | ${completed}/${total} tasks (${progress}%)"
+done)
+```
+
+2. **Present options to user** (using AskUserQuestion tool):
+
+Format output into numbered list:
+```
+Multiple active workflow sessions detected. Please select one:
+
+1. WFS-auth-system | Authentication System | 3/5 tasks (60%)
+2. WFS-payment-module | Payment Integration | 0/8 tasks (0%)
+3. WFS-ui-redesign | UI Redesign | 7/10 tasks (70%)
+
+Which session do you want to execute?
+```
+
+Use AskUserQuestion tool to get user selection. User can provide:
+- Session number (e.g., "1", "2", "3")
+- Full session ID (e.g., "WFS-auth-system")
+- Partial session ID (e.g., "auth-system")
+
+3. **Parse user response**:
+- Extract session ID from user input by matching against the session list
+- Validate the selection exists
+
+4. **Confirm selection** to user:
+```
+✓ Selected session: WFS-auth-system (Authentication System)
+  Progress: 3/5 tasks (60%)
+```
+
+Continue to Phase 2.
+
+#### Step 1.3: Load Session Metadata
+```bash
+bash(cat .workflow/active/${sessionId}/workflow-session.json)
+```
+
+**Output**: Store session metadata in memory
+**DO NOT read task JSONs yet** - defer until execution phase (lazy loading)
+
+**Resume Mode**: This entire phase is skipped when `--resume-session="session-id"` flag is provided.
 
 ### Phase 2: Planning Document Analysis
 **Applies to**: Normal mode only (skipped in resume mode)