feat: always-on ELI16 + branch detection (v0.4.3) (#108)

* feat: always-on ELI16 + branch detection in preamble

- Add _BRANCH detection to preamble bash block (git branch --show-current)
- Merge ELI16 rules into default AskUserQuestion format (always-on)
- Remove _SESSIONS >= 3 conditional — better questions always
- Add simplification rules: plain English, no jargon, no raw function names
- Update tests for branch detection and simplification regression guard

* chore: bump version and changelog (v0.4.3)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

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Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

VERSION

@@ -1 +1 @@
-0.4.2
+0.4.3