Git inspection collapses nested untracked files and omits them from changed-only context #107

Problem

When source files are created under a new untracked directory, Git inspection reports a directory entry such as src/ rather than the individual file paths. Downstream changed-only context can consequently omit all new source code. This was reproduced while building AI Threat Lab with ai-dev-cli-tools 1.3.0, against main commit 5c9f1b7bd4677d32b1650ebd62519044072e599a.

Reproduction

1. Initialize a Git repository.
2. Create src/new_package/service.py containing a small Python function without staging the directory.
3. Run ai-dev git inspect --json.
4. Run ai-dev context build --changed-only --explain --json.

Observed: Git inspection lists src/ as an untracked/changed file; changed-only context can return no selected source files.

Expected: src/new_package/service.py is reported as an untracked/changed file and is eligible for context selection and symbol analysis.

Cause and proposed fix

src/ai_dev_tools/git/inspect.py invokes git status --porcelain=v2 --branch -z, whose default untracked mode collapses directories. Add --untracked-files=all to that same invocation. Preserve NUL-delimited paths and Git ignore rules without adding another subprocess.

Acceptance criteria

• A nested untracked Python file is included in changed-file and context reports.
• Paths with spaces work.
• Git-ignored directories remain excluded.
• Symbol analysis includes functions in new untracked source files.
• Status inspection still uses one Git subprocess.

Existing patch and evidence

Patch preserved in PR #105 (closed in favor of this issue at the maintainer's request), commit 23b4daff33ab8d202719d9e31e108d14bedc848c.

Two new regression tests failed before the fix and passed after it. Focused Git/context suites: 30 passed. Full local suite: 733 passed, 6 skipped; coverage gate 90%; Ruff and package build passed. PR CI, Docs and CodeQL subsequently passed. The separate benchmark typing failure found during local validation is tracked independently.

This issue replaces PR #105 as the work item; no patch has been merged.