Replace legacy scripts/ with git-repokit-common subtree

[djdarcy]

Replace legacy scripts/ with git-repokit-common subtree

Problem

scripts/ contains a divergent, older copy of git hooks and version management that was created before git-repokit-common was extracted as a shared project. The two have drifted:

• dazzlecmd uses bash update-version.sh; repokit-common uses Python sync-versions.py
• dazzlecmd hooks have hardcoded src/dazzlecmd/ paths; repokit-common auto-detects package dirs
• dazzlecmd pre-push uses py_compile glob; repokit-common uses compileall (handles src/ layout)
• repokit-common has additional tools: gh_issue_full.py, gh_sub_issues.py, search_sesslog.py, safe_move.sh

What needs to happen

1. Stash or commit all outstanding uncommitted work first -- git subtree add requires a completely clean working tree (including submodules)
2. Remove existing scripts/ from git
3. git subtree add --prefix=scripts repokit-common main --squash
4. Add [tool.repokit-common] config to pyproject.toml:

   [tool.repokit-common]
   version-source = "src/dazzlecmd/_version.py"
   changelog = "CHANGELOG.md"
   repo-url = "https://github.com/DazzleTools/dazzlecmd"
   tag-prefix = "v"
   tag-format = "human"
   private-patterns = ["private/", ".env"]

5. Run bash scripts/install-hooks.sh to install new hooks
6. Verify hooks work: commit, push, tag push

Gotcha: clean working tree required

git subtree add refuses to run with ANY dirty files -- even unrelated ones, even submodules with modified content. The wtf submodule's nested tools/core/restarted submodule was dirty, plus untracked directories like projects/dazzletools/private-init/ blocked it. Best to do this when the tree is genuinely clean.

Upstream already prepared

• repokit-common v0.2.3 (61ebd1e) includes the tag-only push skip from this session
• Remote repokit-common already added to dazzlecmd: https://github.com/DazzleTools/git-repokit-common.git
• repokit-common's pre-commit has fallback: tries sync-versions.py first, falls back to update-version.sh

Post-subtree tasks

• Remove scripts.bak/ if it still exists
• Update CLAUDE.md version bump checklist (sync-versions.py replaces manual update-version.sh)
• Consider adding [tool.repokit-common] section to pyproject.toml
• Future updates: git subtree pull --prefix=scripts repokit-common main --squash