feat(agents): link the global rules into dsh too

dsh reads ~/.dsh/AGENTS.md, plus ~/.agents/AGENTS.md from 0.2.1-alpha.2;
identical content renders once.

home/base/tui/agents/README.md

@@ -29,6 +29,10 @@ settings that bite.
 | OpenCode   | `~/.config/opencode/AGENTS.md` |
 | Pi         | `~/.pi/agent/AGENTS.md`        |
 | Cross-tool | `~/.agents/AGENTS.md`          |
+| dsh        | `~/.dsh/AGENTS.md`             |
+
+dsh reads both `~/.dsh/AGENTS.md` (`$DSH_HOME`) and, from `0.2.1-alpha.2` on, `~/.agents/AGENTS.md`
+(`$DSH_AGENTS_HOME`); identical content renders once.
 
 Out-of-store means an edit to `agents/AGENTS.md` takes effect on the next agent session without a
 Home Manager switch. The trade-off is that the rules stay writable in the checkout; use a store

home/base/tui/agents/dsh.md

@@ -39,3 +39,13 @@ The `dsh-base` bundle sets `agent-default-model` to the API-key route (`deepseek
 `DEEPSEEK_API_KEY` fails new sessions with `ACCOUNT_SIGN_IN_REQUIRED`.
 
 In this repository, `just dsh-web` boots the web profile through mihomo's mixed port.
+
+## Global rules
+
+`dsh-base` already mounts `dsh-agent-instructions` (`maxBytes: 65536`) and `rules.nix` links
+`agents/AGENTS.md` into both scopes it reads — `$DSH_HOME/AGENTS.md` and, from `0.2.1-alpha.2` on,
+`$DSH_AGENTS_HOME/AGENTS.md` — so no patch row is needed; identical content renders once.
+
+- The scopes come from the environment: `0.2.1-alpha.2` removed the row's `dshHome` / `agentsHome`.
+- Nested `AGENTS.md` files are discovered by `read` / `write` / `edit`, not by `cd` inside `bash`,
+  and nothing is watched: an external edit lands on the next such call, or on resume.

home/base/tui/agents/rules.nix

@@ -12,7 +12,8 @@ in
   home.file = {
     ".codex/AGENTS.md".source = link; # Codex
     ".pi/agent/AGENTS.md".source = link; # Pi
-    ".agents/AGENTS.md".source = link; # cross-tool
+    ".agents/AGENTS.md".source = link; # cross-tool; dsh's `$DSH_AGENTS_HOME` from 0.2.1-alpha.2
+    ".dsh/AGENTS.md".source = link; # dsh's `$DSH_HOME`, its only global scope before that
   };
 
   xdg.configFile."opencode/AGENTS.md".source = link; # OpenCode