Fix _find_skill: use iter_skill_index_files to follow symlinks

[wildnewton]

Problem

_find_skill() used Path.rglob("SKILL.md") which does NOT follow symlinks in Python 3.11. This meant any skill directory reached through a symlink was invisible to skill_manage, even though skill_view could load it (via iter_skill_index_files → os.walk(followlinks=True)).

Root Cause

_find_skill → rglob() (no follow_symlinks) ≠ skill_view → iter_skill_index_files → os.walk(followlinks=True)

When a skill is symlinked (e.g., from a project directory into the profile's skills dir), skill_view can load it but skill_manage reports "not found." This asymmetry caused agents to fall back to action='create', which produced nested duplicate skills that broke cron scheduler resolution.

Fix

Replace rglob("SKILL.md") with iter_skill_index_files(skills_dir, "SKILL.md") — the same function skill_view uses.

TDD

• 🔴 RED: test that _find_skill discovers a symlinked skill directory
• 🟢 GREEN: 2-line change in _find_skill + import

Related

• fix: add collision guard in _create_skill to prevent silent skill nesting #60945: collision detection guard for create action
• fix(cron): only advance next_run_at for jobs that are actually dispatched #60946: scheduler next_run_at on skip

[alt-glitch]

This was generated by AI during triage.

Duplicate of #35244 (earliest open, canonical) which fixes #35184 with the identical mechanism: replace Path.rglob("SKILL.md") (doesn't follow symlinks) with iter_skill_index_files (the same os.walk(followlinks=True) helper skill_view uses). See also #56423 (same swap at both _find_skill call sites) and #35299 (competing rglob_follow() helper approach).

[teknium1]

Thanks for tracing the active-profile discovery mismatch. The current main path still uses rglob() at tools/skill_manager_tool.py:597, while iter_skill_index_files() follows links at agent/skill_utils.py:796, so the proposed direction is sound.

Problems

• The sibling cross-profile lookup still uses rglob() at tools/skill_manager_tool.py:661; it is consumed by _skill_not_found_error() at tools/skill_manager_tool.py:683. Apply the same iterator there and cover that path.
• The added test creates a symlink without handling unavailable symlink support. Existing tests in this file use a graceful OSError skip pattern at tests/tools/test_skill_manager_tool.py:357-360 and 472-475.

Suggested changes

• Use iter_skill_index_files() in both finders and add a cross-profile regression.
• Make the new symlink test skip when link creation is unsupported.

Automated hermes-sweeper review.