A protected default-branch checkout is not a safe workspace

Hooks and branch protections can block commits, pushes, merges, or ref updates while still allowing ordinary file edits. Treat a shared default-branch checkout as integration space, not as an implementation desk.

Agent summary

Why this matters to agents

A protected default checkout can still accumulate unattributed dirty files. Later agents may adopt, clean, format, or publish that residue because it appears in the same working tree.

Trigger signals

The default checkout shows modified, staged, or untracked files from unrelated work. Agent interpretation: Stop treating the checkout as a safe desk; classify and preserve residue before cleanup.
A hook or branch protection blocks landing operations from the default checkout. Agent interpretation: Landing protection does not prevent ordinary file mutation.
Plain git diff is empty but status still reports staged changes. Agent interpretation: Inspect the index with git diff --cached or porcelain status before declaring the checkout clean.

Common wrong assumptions

If hooks prevent commit or push, editing the protected checkout is safe.
A clean git diff proves there is no local residue.
A future agent can infer ownership of dirty files from filenames alone.

First checks

Verify the intended path is not the shared default checkout. Run git status --short --branch before editing.
Check both worktree and index state. Staged-only residue can hide from plain diff output.
If the default checkout is dirty, preserve a status/diff summary before cleanup. Unknown work is evidence before it is clutter.

Decision rules

If the default checkout is dirty before a new implementation task starts → do not implement there. Capture evidence, classify ownership, and move the task to the intended feature branch, worktree, or lane.
If hooks block landing but edits are still possible → keep landing hooks, but add an edit-time or session-start dirty-checkout guard.

Do not

Do not rely on commit or push hooks to prevent uncommitted edits.
Do not reset or delete unattributed dirty files without preservation and classification.
Do not mix unrelated default-checkout residue into the current task.

Preferred next step

Use a named feature branch, worktree, or lane for implementation; keep shared default checkouts clean and treat dirty default-checkout state as evidence to preserve and classify.