* perf(ci): optimize autofix pipeline — fast-track, skip duplicate build, scoped tests (#6196)
Three optimizations to reduce autofix wall-clock from ~48 min to ~28-35 min:
1. Fast-track decision: skip LLM assessment for trusted triggers
(workflow_dispatch with explicit issue, issues:labeled event).
2. Skip duplicate build: set QWEN_SKIP_PREPARE=1 so npm ci does not
re-run the prepare hook that builds+bundles before the explicit
build step.
3. Scoped verification tests: run only changed-file tests via
--changed instead of full per-package suites. Full regression
is covered by regular CI on the PR.
Also hardens live test gating (require QWEN_CODE_RUN_LIVE_TESTS=1)
and increases crawler test timeout to 30s.
* refactor(ci): simplify verification gate package discovery
Replace 30-line inline Node script with the original one-liner
`grep -oE '^packages/[^/]+'`. The Node script checked for
package.json existence and test scripts, but `--if-present` already
handles missing test scripts and all workspace dirs have package.json.
Addresses design-review item #7.
* fix(ci): tighten autofix changed-test gate
