fix: resolve all CI test failures (19 fixes across 6 files) (#519)

- canonical-session: fall back to JSON file recording when the loaded
  state-store module has no writer methods (factory vs instance)
- install-executor: skip node_modules and .git dirs in listFilesRecursive
  to prevent ETIMEDOUT copying thousands of .opencode dependency files
- ecc.js: increase maxBuffer to 10MB for spawned subcommands to prevent
  ENOBUFS on large install plan JSON output
- install-apply.test: update Cursor and Antigravity path assertions to
  match flattened rule layout and remapped dirs (workflows, skills)
- ecc.test: increase maxBuffer in test runner to handle large output
- orchestrate-codex-worker.sh: guard against unreadable task file before
  cat, write failure status and handoff artifacts on early exit

tests/scripts/ecc.test.js

@@ -14,6 +14,7 @@ function runCli(args, options = {}) {
   return spawnSync('node', [SCRIPT, ...args], {
     encoding: 'utf8',
     cwd: options.cwd || process.cwd(),
+    maxBuffer: 10 * 1024 * 1024,
     env: {
       ...process.env,
       ...(options.env || {}),