chore(gitignore): ignore session/debugging artifacts and tool caches

Add patterns for runtime residue that should never be committed:
- .dori/ - dori-sync sibling cache
- .playwright-mcp/ - Playwright MCP browser cache
- .debug-journal*.md - debugging skill workspace journals
- session-ses_*.md - exported session dumps

.gitignore

@@ -37,3 +37,9 @@ oauth-success.html
 *.bun-build
 .omx/
 .dori-sync/
+.dori/
+.playwright-mcp/
+
+# Debugging / session artifacts (skill workspace residue)
+.debug-journal*.md
+session-ses_*.md