Remove nightly cron trigger from full test suite

Nightly runs are redundant when running full tests on every merge to develop.

Benefits of removing nightly:
- Reduces CI resource usage
- Simplifies maintenance
- Full tests still run on:
  - Every merge to develop (frequent)
  - Manual trigger (when needed)
  - PR with "test:full" label (on-demand)

Nightly only makes sense if:
- Merges are infrequent (days/weeks apart)
- Tests have time-dependent edge cases
- External dependencies need regular validation

For active development with frequent merges, running full tests
on every develop merge provides sufficient coverage.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

.github/workflows/11-test-full-EXPERIMENTAL.yaml

@@ -11,8 +11,6 @@ on:
     branches:
       - develop
       # Run full suite after merge to develop - Tier 3 complete coverage
-  schedule:
-    - cron: '0 2 * * *'  # 2 AM daily
   pull_request:
     types: [labeled]
     # Run if PR has "test:full" label