fix(hook): make hook-augment work on Windows drive-letter paths

[catsmonster]

What

Fixes the hook-augment PreToolUse Grep/Glob augmenter being a structural no-op on Windows.

Closes #618.

Why

src/cli/hook_augment.c had two POSIX-only path guards that a Windows drive-letter cwd (C:\repo / C:/repo) can never satisfy:

1. cbm_cmd_hook_augment, _WIN32 branch — if (!cwd || cwd[0] != '/') returned early on every invocation (a Windows absolute path never starts with /).
2. ha_resolve_and_query walk-up loop — for (... && dir[0] == '/'; ...) never iterated for a C:/... path, and the parent-climb terminator assumed a /-root.

cbm_project_name_from_path already handles Windows paths (it produced the indexed project name from the C:\... root), so the fix is purely in these path assumptions.

How

• Add cbm_hook_path_is_abs() — true for POSIX "/..." and Windows "X:/..." roots.
• Normalize \ → / on the Windows cwd before validation.
• Loop while cbm_hook_path_is_abs(dir); stop the parent-climb at the drive root (X:/) as well as the POSIX root.
• POSIX path unchanged (the previous cwd[0] != '/' → getcwd fallback is preserved via the predicate).

Testing

The predicate is exposed as cbm_hook_path_is_abs (declared in cli.h) so it has direct regression coverage.

• Regression test tests/test_cli.c::cli_hook_augment_path_is_abs (registered in the cli suite): asserts the predicate accepts /..., C:/Users/me/proj, C:/, C:, d:/... and rejects relative/path, proj, "", NULL. It fails on the old POSIX-only guard and passes after the fix. Being pure string logic, it also runs on the Linux CI.
• Walk self-test (standalone, run locally): for C:\Users\me\proj the resolver queries C:/Users/me/proj → C:/Users/me → C:/Users (stops one below the drive root), exactly symmetric to POSIX /home/u/proj → /home/u → /home.
• clang-format clean on all three changed files; clang -fsyntax-only -I src -I vendored src/cli/hook_augment.c passes.
• Not yet built through the full toolchain — I don't have make/zlib locally, so I'm relying on Windows CI to confirm the compile/link. Flagging that explicitly.

clang-tidy note: my additions follow the file's existing idiom ([4096] buffers, unchecked snprintf, drive-index access) that the surrounding code already uses, so I kept them consistent rather than adding one-off named-constants/void-casts. (CI runs lint.sh --ci, which skips clang-tidy.)

Notes

The "never block a tool" guarantee is untouched — every path still ends in exit 0 with output written exactly once. This only changes whether context is added on Windows; it can still never deny a tool. Fits under the Windows umbrella tracker #394.

[DeusData]

Huge thanks for opening this PR and for the work you put into it.

The maintainer shop is currently full, so this may sit for a bit before it gets a proper review. We will come back to this as soon as possible with real feedback; I wanted to make sure it did not sit unacknowledged in the meantime.

[DeusData]

Thanks, this is targeted at #618. Before merge, please remove generated/co-author/session metadata from the non-merge commit. If CI flags DCO on the merge commit, please refresh the branch; otherwise please include Windows hook-augment smoke output.

[Copilot]

Pull request overview

Fixes hook-augment on Windows by removing POSIX-only absolute-path assumptions that caused the augmenter to always early-exit (drive-letter cwd), enabling the Grep/Glob PreToolUse context augmentation to run on Windows paths while preserving the “never block a tool” behavior.

Changes:

• Introduces cbm_hook_path_is_abs() to recognize both POSIX (/...) and Windows drive-rooted (X:/...) absolute paths.
• Normalizes Windows cwd backslashes (\) to forward slashes (/) before validation and walk-up resolution.
• Updates the walk-up loop and parent-climb termination to work correctly with drive-letter roots, and adds a regression test.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
src/cli/hook_augment.c	Adds cross-platform absolute-path detection, normalizes Windows cwd, and makes the directory walk-up logic work with drive-letter roots.
src/cli/cli.h	Exposes cbm_hook_path_is_abs() for direct test coverage.
tests/test_cli.c	Adds regression coverage for Windows drive-letter absolute-path handling.

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[catsmonster]

Done in 4bb9eff — the comment now states the predicate also treats a bare X: as absolute (matching d[2] == '\0' and the cbm_hook_path_is_abs("C:") test case).

[catsmonster]

Done in 4bb9eff — the comment now states the predicate also treats a bare X: as absolute (matching d[2] == '\0' and the cbm_hook_path_is_abs("C:") test case).

[catsmonster]

Both points addressed.

1. Co-author/session metadata removed. Rebased onto latest main; the branch is now a single commit (c234f17) carrying only the DCO Signed-off-by — no Co-Authored-By. The earlier Update branch merge commit is gone, so history is linear.

2. Windows hook-augment smoke output. Built this branch on Windows 10 with the MSYS2 CLANG64 toolchain (same as the test-windows / smoke CI jobs: mingw-w64-clang-x86_64-{clang,zlib}), then ran the augmenter against a freshly indexed dummy repo with a drive-letter cwd:

# dummy repo at C:\tmp\smoke-demo — app.js defining function smokeTestHandler()
$ codebase-memory-mcp cli index_repository '{"repo_path":"C:/tmp/smoke-demo"}'
{"project":"C-tmp-smoke-demo","nodes":6,"edges":5,...,"status":"indexed"}

$ PAYLOAD='{"hook_event_name":"PreToolUse","tool_name":"Grep","cwd":"C:/tmp/smoke-demo","tool_input":{"pattern":"smokeTestHandler"}}'

# BEFORE — release v0.8.1 (POSIX-only path guard):
$ printf '%s' "$PAYLOAD" | codebase-memory-mcp-0.8.1 hook-augment | wc -c
0

# AFTER — this PR:
$ printf '%s' "$PAYLOAD" | ./build/c/codebase-memory-mcp hook-augment
{"hookSpecificOutput":{"hookEventName":"PreToolUse","additionalContext":"[codebase-memory] 1 graph symbol(s) match \"smokeTestHandler\" (structured context; your search results below are unaffected):\n- C-tmp-smoke-demo.app.smokeTestHandler  app.js  Function"}}

Same indexed project, same drive-letter cwd: 0.8.1 emits nothing, the patched build emits additionalContext. The cli_hook_augment_path_is_abs unit test added here also passes on the test-windows CI job.