feat: add task completion tracking and template usage

- Updated tasks-workflow.sh to use tasks-template.md for Progress Summary
- Updated implement-workflow.sh specialist prompts to call task-tracker mark-done-with-notes
- Added detailed explanations of what task-tracker functions do
- Enables automatic velocity tracking, ETA calculation, and bottleneck detection

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

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

Author: marcusgoll

.spec-flow/scripts/bash/implement-workflow.sh

@@ -420,7 +420,11 @@ ${batch.tasks.map(t => `- ${t.id} [${t.phase || 'GENERAL'}]: ${t.desc}`).join('\
    - GREEN: Minimal implementation to pass test, commit when passing
    - REFACTOR: Clean up code while keeping tests green, commit
 4. For general tasks: Implement, test, commit
-5. Update task status in ${notesFile} with ✅ ${t.id} after completion
+5. **Task Completion Tracking** (MANDATORY after EACH successful task):
+   - Call task-tracker to mark task complete and update Progress Summary
+   - Format: .spec-flow/scripts/bash/task-tracker.sh mark-done-with-notes -TaskId "TXXX" -Notes "Implementation summary (1-2 sentences)" -Evidence "pytest: NN/NN passing" -Coverage "NN% line, NN% branch" -CommitHash "$(git rev-parse --short HEAD)" -Duration "XXmin" -FeatureDir "${featureDir}"
+   - Example: .spec-flow/scripts/bash/task-tracker.sh mark-done-with-notes -TaskId "T001" -Notes "Created Message model with validation" -Evidence "pytest: 25/25 passing" -Coverage "92% line, 88% branch" -CommitHash "$(git rev-parse --short HEAD)" -Duration "15min" -FeatureDir "${featureDir}"
+   - This updates both tasks.md checkbox AND NOTES.md AND Progress Summary velocity metrics
 6. **Error Handling** (MANDATORY):
    - On test failure: Call task-tracker mark-failed BEFORE rollback
    - On linting error: Log to error-log.md with full error output
@@ -702,6 +706,8 @@ Before implementing:
 
 ### Task Status Updates (mandatory)
 
+**CRITICAL**: You MUST call task-tracker for EVERY task (success or failure)
+
 After successful task completion:
 ```bash
 .spec-flow/scripts/bash/task-tracker.sh mark-done-with-notes \
@@ -710,9 +716,16 @@ After successful task completion:
   -Evidence "pytest: NN/NN passing" or "jest: NN/NN passing, a11y: 0 violations" \
   -Coverage "NN% line, NN% branch (+ΔΔ%)" \
   -CommitHash "$(git rev-parse --short HEAD)" \
+  -Duration "XXmin" \
   -FeatureDir "$FEATURE_DIR"
 ```
 
+**What this does**:
+- Updates tasks.md checkbox from [ ] to [X]
+- Appends to NOTES.md with ✅ TXXX: Description - duration (timestamp)
+- Updates Progress Summary section with velocity metrics (avg time, ETA, bottlenecks)
+- Enables automatic velocity tracking and bottleneck detection
+
 On task failure:
 ```bash
 # MANDATORY: Log error before rollback
@@ -725,6 +738,11 @@ On task failure:
 git restore .
 ```
 
+**What this does**:
+- Appends to error-log.md with ❌ TXXX and error details
+- Does NOT update tasks.md (leaves checkbox unchecked for retry)
+- Enables debugging with complete error history
+
 ---
 
 ## Error Handling

.spec-flow/scripts/bash/tasks-workflow.sh

@@ -259,10 +259,15 @@ echo ""
 # - Phase N: Polish & Cross-Cutting Concerns
 # - [TEST GUARDRAILS] (if tests requested)
 
-echo "Generating tasks.md..."
+echo "Generating tasks.md from template..."
 echo ""
 
-# Claude Code writes tasks.md with format:
+# Claude Code MUST use .spec-flow/templates/tasks-template.md as the base structure
+# Read the template file and populate it with generated tasks
+#
+# Template sections to populate:
+# 1. Progress Summary (leave as template placeholders - auto-updated by task-tracker)
+# 2. Task Format (follow this structure):
 # - [ ] [TID] [P?] [Story?] Description with file path
 #   - REUSE: ExistingService (path/to/service.py)
 #   - Pattern: path/to/similar/file.py