chore(matrix/technical-writer): make codebase-memory Git Bash-callable

## Epic and coordination tracks - Epic: #1495 - Track: #1496 ## Primary file `D:\0_repos\AgentsCommander_iac\.ac\_agent_technical-writer\skills\codebase-memory\SKILL.md` ## Atomicity and compile invariant - This issue owns exactly one primary file. - Allowed consumer-only files: none. - Any other changed file fails this issue. Create another one-file issue instead of expanding scope. - Every commit and the final merge must leave `main` compiling; a broken intermediate repository is forbidden. ## Scope - Replace PowerShell-only invocation prose with a supported Git Bash entry path where available, otherwise an explicit `pwsh.exe -NoProfile -File` bridge resolved from the installed `SKILL.md` location. - Preserve the full Codebase Memory gate, freshness, graph-operation, fallback, and self-handoff rules. - Keep responsibility, authority, and product policy out of this skill; do not edit `Role.md`. ## Acceptance criteria - From the technical-writer agent's Git Bash session, paths with spaces resolve correctly, the full gate returns eady, and one graph operation succeeds. - No unlabeled `$env:`, `Join-Path`, call operator, or PowerShell cmdlet syntax is presented as Bash. - All other canonical Agent Matrix files remain byte-identical. ## Dependencies - Blocked by #1503 - test(windows): add real Git Bash ConPTY host coverage. ## Required verification - Hash every canonical file in the owning Agent Matrix before and after; the changed set must equal the primary path exactly. - Prove `Role.md` and every other skill remain byte-identical. - Prove `repo-AgentsCommander` stayed at its starting commit with an empty diff. - From the unchanged repository run `cargo check --workspace --all-targets`, `npm run typecheck`, and `npm run build`. - Reload the changed skill in the owning agent and run its acceptance smoke. - From Git Bash, require a fresh Codebase Memory full gate returning `ready` plus one graph operation. - This external Matrix change follows Matrix governance and must not use an application-repository implementation branch. ## Non-goals - Expanding this ticket to another primary file. - Introducing a new Rust module-pair dependency or changing the existing cyclic-SCC member set. - Mechanically rewriting intentional PowerShell workflows, historical evidence, or Windows data paths.