Harden hook-kit guard precision: overwrite-guard tool/field coverage and push-detail generic-word matching

[daegunjhy]

Problem

Two hook-kit guard scripts pass a permissive check where a stricter one is needed, letting the exact case they exist to catch slip through. Both were flagged by CodeRabbit's post-merge review of #292 and verified still present on current local HEAD.

1. block-write-file-overwrite.sh — missing Write/file_path coverage

block-write-file-overwrite.sh only recognizes the Claude tool names write_to_file / default_api:write_to_file, and only reads .tool_input.TargetFile / .tool_input.target_file for the target path. It never checks tool_name == "Write" nor .tool_input.file_path (Claude Code's actual Write tool uses file_path, not TargetFile).

edit-guard.sh's own check_write_file_overwrite does recognize Write|write_to_file, but it exempts */task.md and */scratch/* paths outright — relying on block-write-file-overwrite.sh to cover the task.md case specifically. Since block-write-file-overwrite.sh never fires for a plain Write tool call using file_path, a Write call targeting an existing task.md with Overwrite: true can pass both guards unblocked.

2. ask-guard.sh — generic-word push-detail bypass

In check_push_without_details(), has_remote is set to 1 whenever the option text matches generic words like remote|branch|local|main|master — not an actual remote/branch pair (e.g. origin/local). Similarly has_commit_info is set to 1 for the bare word commit — not an actual SHA or a labeled commit subject.

An option such as "Push the commit to main" satisfies both checks (main → has_remote, commit → has_commit_info) without identifying any concrete remote, branch, SHA, or commit subject — defeating the intent of the git-push-detail HARD STOP the guard exists to enforce.

Scope

1. skills/hook-kit/resources/block-write-file-overwrite.sh:
   • Recognize tool_name == "Write" in addition to write_to_file / default_api:write_to_file for the Claude branch.
   • Read .tool_input.file_path as a fallback target-path field alongside .tool_input.TargetFile / .tool_input.target_file.
   • Coordinate with edit-guard.sh's task.md/scratch exemption so the two guards don't leave a combined gap — either this guard now fully covers what edit-guard.sh exempts, or the exemption is narrowed to match this guard's actual coverage.
2. skills/hook-kit/resources/ask-guard.sh check_push_without_details():
   • Require an actual remote-and-branch pair (e.g. origin/<branch> shape, or an explicit branch name token) for has_remote, not bare remote|branch|local|main|master.
   • Require a real commit SHA ([0-9a-f]{7,40}) or an explicitly labeled commit subject for has_commit_info, not the bare word commit.
3. Add or extend self-tests for both scripts covering the previously-passing bypass cases (a Write call with file_path targeting an existing task.md; an ask option like "Push the commit to main").

Verification

Feature	Procedure	Expected Result
Write-tool overwrite blocked	Pipe a Claude Write tool_name payload with file_path pointing at an existing task.md and Overwrite: true into block-write-file-overwrite.sh	Guard denies (exit 2 / stderr DENIED)
Combined guard coverage	Confirm edit-guard.sh's task.md/scratch exemption and block-write-file-overwrite.sh's coverage together leave no gap for registered Write/write_to_file tool names	No case passes both guards unblocked
Push-detail generic bypass blocked	Run ask-guard.sh against an ask option text "Push the commit to main"	Guard denies (previously passed)
Push-detail concrete case still passes	Run ask-guard.sh against an ask option text naming an explicit remote/branch (e.g. origin/local) and a commit SHA or labeled subject	Guard allows
Existing self-tests	Run each script's existing self-test/fixture suite	All still pass