docs(agents): commit each completed unit of work as it lands

Standing rule: commit per related edit with detailed conventional-commit
messages as each project section finishes, instead of batching a whole
session into one giant commit. Committing is local bookkeeping; pushing
stays a separate, explicit decision. Ordering guidance added so stacked
trees compile (service before handler, guard before dependent feature).

AGENTS.md

@@ -4,6 +4,32 @@ Standing rules for any agent or developer working in this repo.
 Project-wide context lives in the sibling repos' AGENTS.md files
 (../bookhoard-app/AGENTS.md is the Android client's).
 
+## Commit as each unit of work completes — ALWAYS apply
+
+Commit when a logically complete piece of the project is done — a fix,
+a feature slice, a schema change, a docs/test batch — before moving on
+to the next piece. Do not hold a whole session's work for one giant
+end-of-session commit, and never push uncommitted work aside until the
+tree is clean.
+
+- **One commit per related edit.** If the changed files serve more than
+  one purpose, they are separate commits; only share a commit when you
+  are sure every file in it is the same related edit. Generated
+  artifacts (templ codegen, sqlc output, vite/tailwind build output,
+  bruno/openapi mirrors) commit with the source change that produced
+  them.
+- **Detailed messages**, in the repo's conventional-commit style
+  (`fix(scanner): …`, `feat(issues): …`) with a body that says WHY the
+  change exists, what behavior changed, and any precedent it follows —
+  not just what the diff shows. The body is how the next agent (and
+  git history) arbitrates "test stale vs code changed".
+- **Ordering**: stack commits so each tree compiles where practical
+  (a service before the handler that calls it, a guard before the
+  feature that relies on it).
+- **Committing ≠ pushing.** Commits are local bookkeeping and land as
+  work completes; pushing (once, after the last commit) is the author's
+  call. Never push half-finished units just because they were committed.
+
 ## Rendering ownership (templ vs TypeScript) — ALWAYS apply
 
 The point of templ + htmx + Alpine is: the server renders the UI, and