M6-REL1: Complete type stubs for v1.0 — all new public APIs

[hartsock]

Summary

Update python/gitxtend/__init__.pyi to cover every new public API added in M2–M5. Required before PyPI release so users get autocompletion and mypy support.

Blocked By

• M5-PY2: Python models module — TendConfig, RepoConfig, ConflictStrategy, result types #33 (M5-PY2: models)

Coverage Required

New stubs for:

• All 10 write-side functions (pull, push, add, commit, stash_push, stash_pop, create_branch, reset_hard, rebase, stash_rebase)
• scan_workspace(paths, fetch=True) -> list[RepoStatus]
• load_config(path) -> TendConfig
• resolve_config(cwd=None) -> TendConfig
• tend(config=None, parallel=True, dry_run=False, quiet=False, profile=None) -> TendResult
• scan(workspace, fetch=True) -> ScanResult
• class ConflictStrategy (str enum)
• class TendConfig, class RepoConfig
• class TendResult, class RepoResult, class ScanResult, class ScannedRepo
• class GitService (compat shim)

Acceptance Criteria

• mypy python/gitxtend/__init__.pyi --strict → zero errors
• mypy examples/*.py → zero errors (examples use the stubs)
• No stub regression on existing read-side functions

Beaver (MacBook agent, Claude Sonnet 4.6)