feat: Claude Code slash commands for Task Master (#774)

* Fix Cursor deeplink installation with copy-paste instructions (#723)

* fix: expand-task (#755)

* docs: Update o3 model price (#751)

* docs: Auto-update and format models.md

* docs: Auto-update and format models.md

* feat: Add Claude Code task master commands

Adds Task Master slash commands for Claude Code under /project:tm/ namespace

---------

Co-authored-by: Joe Danziger <joe@ticc.net>
Co-authored-by: Ralph Khreish <35776126+Crunchyman-ralph@users.noreply.github.com>
Co-authored-by: Volodymyr Zahorniak <7808206+zahorniak@users.noreply.github.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: neno-is-ooo <204701868+neno-is-ooo@users.noreply.github.com>

.claude/commands/tm/set-status/to-cancelled.md

@@ -0,0 +1,55 @@
+Cancel a task permanently.
+
+Arguments: $ARGUMENTS (task ID)
+
+## Cancelling a Task
+
+This status indicates a task is no longer needed and won't be completed.
+
+## Valid Reasons for Cancellation
+
+- Requirements changed
+- Feature deprecated
+- Duplicate of another task
+- Strategic pivot
+- Technical approach invalidated
+
+## Pre-Cancellation Checks
+
+1. Confirm no critical dependencies
+2. Check for partial implementation
+3. Verify cancellation rationale
+4. Document lessons learned
+
+## Execution
+
+```bash
+task-master set-status --id=$ARGUMENTS --status=cancelled
+```
+
+## Cancellation Impact
+
+When cancelling:
+1. **Dependency Updates**
+   - Notify dependent tasks
+   - Update project scope
+   - Recalculate timelines
+
+2. **Clean-up Actions**
+   - Remove related branches
+   - Archive any work done
+   - Update documentation
+   - Close related issues
+
+3. **Learning Capture**
+   - Document why cancelled
+   - Note what was learned
+   - Update estimation models
+   - Prevent future duplicates
+
+## Historical Preservation
+
+- Keep for reference
+- Tag with cancellation reason
+- Link to replacement if any
+- Maintain audit trail