test: Add subcommand documentation verification (#1597)

* test: Add subcommand documentation verification

Enhances help sync test to verify:
- tags subcommands use new unified structure (tags add, tags use, etc.)
- deprecated standalone tag commands are not documented
- list command options are documented (--watch, --ready, --blocking, etc.)
- list format options are documented (--json, -f, -c)

Closes #1596

* fix: Remove generate from undocumented list (it is documented)

* Address CodeRabbit PR feedback

- Add clarifying comment for COMMAND_NAME_MAPPINGS to explain legacy command exemption during migration
- Update 'tags add' command args to include missing --from-branch option
- Add changeset documenting test enhancements and minor fixes

* fix: Use task-master-ai instead of @tm/cli in changeset

Changeset validation only allows public package names (task-master-ai, extension).
Changed from internal package name @tm/cli to public package name task-master-ai.

* fix: Prevent test from silently passing when regex fails

Addresses Cursor Bugbot feedback: The test "should not document deprecated
standalone tag commands" now falls back to checking the entire help content
if the Tag Management section regex doesn't match, instead of silently
passing without making any assertions.

This ensures the test always validates that deprecated commands are not
documented, even if the help formatting changes.

---------

Co-authored-by: Ben Coombs <[email protected]>

Author: bjcoombs

.changeset/help-sync-test-enhancements.md

@@ -0,0 +1,14 @@
+---
+"task-master-ai": patch
+---
+
+Enhanced help documentation sync test to verify subcommand structure and improve test maintainability
+
+This changeset adds comprehensive help documentation sync tests that verify:
+- Tags subcommand documentation matches the new 'tags add/use/remove' structure
+- Deprecated tag commands (add-tag, use-tag, delete-tag) are not documented
+- List command options are properly documented with all variants
+
+Also includes minor fixes:
+- Updated 'tags add' command args to include missing --from-branch option
+- Added clarifying comments for legacy command mappings during migration