fix: update /tmp references to use KUGETSU_TEMP_DIR

Replace /tmp references with ${KUGETSU_TEMP_DIR:-~/.local/share/opencode/tool-output}
since opencode blocks /tmp access in headless mode.

Updated files:
- docs/SUBAGENT_WORKFLOW.md
- docs/hermes-communication-patterns.md
- docs/hermes-setup.md
- docs/kugetsu-setup.md
- docs/opencode-usage.md
- skills/kugetsu/pm/SKILL.md

Fixes #73

docs/hermes-setup.md

@@ -180,7 +180,8 @@ For Kugetsu's parallel workflow, prefer `terminal(opencode run ...)` for coding
 
 ```bash
 # One-shot task (blocks until complete)
-terminal(command="opencode run 'Fix issue #1: add retry logic'", workdir="/tmp/issue-1")
+# Note: Use KUGETSU_TEMP_DIR instead of /tmp for opencode workdir
+terminal(command="opencode run 'Fix issue #1: add retry logic'", workdir="${KUGETSU_TEMP_DIR:-${HOME}/.local/share/opencode/tool-output}/issue-1")
 
 # Background TUI (interactive, returns session_id)
 terminal(command="opencode", workdir="~/project", background=true, pty=true)
@@ -319,7 +320,7 @@ git push --force-with-lease origin my-branch
    opencode run "Research/fix issue #{N}"
 
 4. Agent Posts to Gitea
-   curl -X POST .../issues/{N}/comments -d @/tmp/findings-{N}.md
+   curl -X POST .../issues/{N}/comments -d @${KUGETSU_TEMP_DIR:-${HOME}/.local/share/opencode/tool-output}/findings-{N}.md
 
 5. User Reviews on Gitea
    Comments on issues/PRs