refactor(skills): convert absolute paths to workspace-relative + relocate agent-sessions.yaml to .hermes/

Changes:
- skills/lib.sh: AGENT_SESSIONS_YAML default moved from ~/PuKi/lab/.../agent-sessions.yaml
  to <workspace_root>/.hermes/agent-sessions.yaml (relative via BASH_SOURCE)
- 6 SKILL.md: descriptions + 'Single source of truth' lines updated to .hermes/agent-sessions.yaml
- 6 SKILL.md: bash examples (~/PuKi/lab/agent_sessions/skills/...) → relative paths
- SKILL.md file:// links converted from absolute to relative (resolves workspace tool warnings)
- tmux-agent-orchestrate-create/SKILL.md: removed outdated wrapper template reference
- lib.sh internal comments: removed /home/godopu16/PuKi/lab example
- All scripts: internal source/path references use relative resolution

Verified on isolated server -L agy-relative-path-test (kill-server after):
- syntax check PASS
- E2E: create_session.sh auto-creates .hermes/agent-sessions.yaml at new location
- status.sh reads new location correctly
- 0 leftover absolute path references
- Global skill non-interference verified
- Main isolated server -L multi-agent-canary untouched

skills/lib.sh

@@ -14,7 +14,9 @@
 # HARD RULE: the agent-sessions.yaml file is only ever written through
 # atomic_dump_yaml. Never `open(yaml_path, 'w')` anywhere else.
 
-AGENT_SESSIONS_YAML="${AGENT_SESSIONS_YAML:-$HOME/PuKi/lab/agent_sessions/agent-sessions.yaml}"
+SKILL_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+WORKSPACE_ROOT="$(cd "$SKILL_DIR/.." && pwd)"
+AGENT_SESSIONS_YAML="${AGENT_SESSIONS_YAML:-$WORKSPACE_ROOT/.hermes/agent-sessions.yaml}"
 
 # ---------------------------------------------------------------------------
 # Tmux Server Isolation support
@@ -126,7 +128,8 @@ PYEOF
 #          '_' -> '-', lowercased, joined with '-'
 #   name = "<slug>-creator-<agent>"
 #
-#   /home/godopu16/PuKi/lab/landing_page/refer_landing_page + claude
+#   Workspace root 기준 상대 해석. 예:
+#     $WORKSPACE_ROOT/landing_page/refer_landing_page + claude
 #       -> landing-page-refer-landing-page-creator-claude
 #
 # Decision (REVIEW P0-A): the actual workspace basename (refer_landing_page)