docs: AGENTS.md: never work on main or a release branch, hardware-specific fixes, git identity

AGENTS.md

@@ -48,6 +48,13 @@ gamescope and the Plasma desktop. Primary target: the Valve Steam Machine
   `<id>_available` is checked via `component_available` (e.g. `machine`
   only on Fremont). Turn-on order is `COMPONENTS` order, turn-off reverse;
   `gaming` must stay first. Dependencies live in `toggle_component`.
+- **Hardware-specific fixes** that belong to a component but aren't a menu
+  row (e.g. `lib/nvidia.sh`: NVIDIA's kernel parameters and early modules
+  for gaming mode, called from `gaming_enable`/`gaming_disable`) detect the
+  hardware themselves, change only what's missing, and undo it on disable.
+  Add them to the source loop in `steamify.sh` and the table in
+  `TECHNICAL.md`. They can't be tested without the hardware: say so in the
+  changelog and keep the branch behind `.no-release-yet` until it was.
 - **Feature versions.** Set `FEATURE_VERSION[<id>]` (`lib/menu.sh`) to the new
   `VERSION` whenever what `<id>_enable` sets up changes (a new component gets
   one too): installs recorded with an older version
@@ -126,7 +133,15 @@ gamescope and the Plasma desktop. Primary target: the Valve Steam Machine
       `sudo apt install gh`, then `gh auth login`) instead of working around
       it. Only the
       release branch's pull request into `main` is the user's: never commit
-      or merge to `main`, the user merges that one.
+      or merge to `main`, the user merges that one. Never work directly on
+      `main` or a `release/*` branch either: edits, even uncommitted ones,
+      go on a `feature/`/`bugfix/` branch (create it before editing; the
+      release branch only gets the version-bump commit and merged PRs).
+      Don't push a new `release/*` branch before it's needed: a push can
+      start CI builds (a dev ISO).
+      A machine without a git identity: pass the repo's author per command
+      (`git -c user.name=... -c user.email=... commit`, taken from `git
+      log`) instead of changing the git config.
       A `.no-release-yet` file at the root of a feature/bugfix branch means
       it must not be merged into the release branch yet (work in progress,
       untested on hardware). When the feature is complete, ask the user