refactor: resolve clawpatch findings

[Jercik]

Resolves all 7 open clawpatch findings (all low-severity maintainability) and refreshes dependencies. Each finding was revalidated by clawpatch (now openFindings: 0), and the full local suite (format, knip, typecheck, lint, fta, tests) passes via the pre-commit hook on every commit.

Clawpatch fixes

• docs: consolidate duplicated README command examples — removed the generic single/multi-target and current-worktree example blocks under Manual Mode that were verbatim duplicates of the Examples section; kept the unique detached-HEAD and sibling-directory examples and pointed Manual Mode at Examples.
• refactor: drop stale executable shebang from cli source — src/cli.ts is compiled to dist/cli.js and run via bin/worktree-remove; it can never run directly (it imports .js paths), so its #!/usr/bin/env -S node --experimental-strip-types shebang and executable bit were misleading. Removed both and converted the action-level process.exit() calls to process.exitCode + return (the idiomatic pattern unicorn/no-process-exit steers toward; the SIGINT handler keeps process.exit(130)). Verified exit codes are unchanged for the no-target, -i non-interactive, --help, and unknown-flag paths.
• refactor: drop restatement comments and verbose jsdoc — deleted top-of-file comments that only restated module names across src/fs and src/git, plus the verbose normalizeBranchName/exitWithMessage/confirm JSDoc blocks in git-helpers.ts.
• test: exercise directoryExists against a real temp directory — replaced the fs.stat mock and the toHaveBeenCalledWith implementation assertion with a behavior-level test over a real temp dir/file, so the test no longer locks the helper to its internal fs choice.
• refactor: thread target names through batch removal results — report-batch-results.ts now counts successes instead of collecting names only to count them; remove-batch.ts asserts the non-empty target once after the length guard and pairs each removal result with its target name, removing the impossible ?? "target" / ?? "unknown target" fallbacks.

Dependency update

• fix(deps): update dependencies — bumped @types/node, fta-check, semantic-release, and oxlint-config-j4k (2.7.2 → 2.7.4) to latest; lockfile deduped. @typescript/native-preview stays on its beta-tagged build (20260421.2) as pinned.
• test: assert directoryExists returns false directly — oxlint-config-j4k 2.7.4 resolves the contradictory vitest matcher rules (prefer-to-be-falsy vs prefer-strict-boolean-matchers), so the test now uses the precise .toBe(false) instead of the earlier .not.toBe(true) workaround.

One pre-existing eslint-disable on exitWithMessage's process.exit in git-helpers.ts was left untouched — load-bearing and out of scope for these findings.