docs: add Communication patterns section to all plugin CLAUDE.md

Standardize named-markdown-link guidance across all plugins so file://
references render as independently clickable links in terminals like
Ghostty (bare file:// URLs only make the first clickable).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

plugins/graceful-handoff/CLAUDE.md

@@ -63,3 +63,20 @@ node --test plugins/graceful-handoff/tests/
 - v1.0.0 (2026-04-19): initial declarative command
 - v2.0.0 (2026-05-01): skill-arkitektur + JSON-pipeline + 3 hooks + auto-trigger (BREAKING)
 - v2.1.0 (2026-05-01): modell-bevisst kontekstvindu — 4-stegs resolution-kjede (used_percentage → payload-size → model-map → 1M default). Fikser for-tidlig auto-handoff på Opus 4.7
+
+## Communication patterns
+
+### Linking to local files
+
+When pointing to local files in responses, always use markdown link syntax with a descriptive name:
+
+- Use `[Human-friendly name](file:///absolute/path)` — never bare `file:///...` URLs or autolinks `<file://...>`.
+- Always use absolute paths. Never `~/` or relative paths.
+- For multiple files, render as a bullet list of named markdown links.
+
+Why: bare `file://` URLs only render the first as clickable across multiple lines. Named markdown links make each entry independently clickable and look cleaner.
+
+Example:
+
+- [Brief](file:///Users/ktg/.../brief.html)
+- [Research summary](file:///Users/ktg/.../research/summary.md)