chore(agents): update dsh-nu to 0.5.0

The lock bump moves the input from 47c813c to b8e30ec. The guide now says which Nushell the bundle builds against and that its pin warns on divergence, names direct script execution as the replacement for a refused shell handoff, and uses a Nushell stderr redirect in the verification snippet.

Assisted-by: DeepSeek Harness (deepseek-flash)

flake.lock

@@ -174,11 +174,11 @@
         "nur-ryan4yin": "nur-ryan4yin"
       },
       "locked": {
-        "lastModified": 1792377933,
-        "narHash": "sha256-xDPXjJG0NdCMNHkp/KZFZ3E7n9Vuu+MBmDi9uIbj+NY=",
+        "lastModified": 1792394981,
+        "narHash": "sha256-ZQuL/y1p4BOC1xWXtLS26YXYpOwVTy3braeX/onuiDk=",
         "owner": "ryan4yin",
         "repo": "dsh-nu",
-        "rev": "47c813c8bd477ae4911a89bd6bd647da057856d1",
+        "rev": "b8e30ec6693ab911513d52730bd664052ef89629",
         "type": "github"
       },
       "original": {

home/base/tui/agents/dsh.md

@@ -57,8 +57,12 @@ on, `$DSH_AGENTS_HOME/AGENTS.md` — so no patch row is needed; identical conten
 `ctx.shell` consumer (model shell tools, background jobs, hook bridges, in-process callers) runs
 `nu --no-config-file -c`, and a command that hands execution to another shell is refused before it
 spawns. The plugin adds Nushell rules and a syntax guide, and rewrites the shell-tool descriptions,
-so the model is told what actually runs. `nu` is the Nixpkgs one, fixed at build time, so it does
-not depend on `PATH`.
+so the model is told what actually runs. `nu` is the Nushell `dsh-nu`'s flake resolves — Nixpkgs',
+through `inputs.nixpkgs.follows` — substituted into the rendered patch at build time, so it does not
+depend on `PATH`. The bundle is tested with Nushell 0.115.1 and warns at evaluation time when the
+resolved Nushell differs; drop the `follows` to build against its own pin instead. A command that
+hands a script file to a shell (`bash scripts/build.sh`) is refused, and the refusal names the
+direct `./scripts/build.sh` spelling; the guard itself is unchanged.
 
 `home/base/tui/agents/packages.nix` calls `dsh-nu.lib.mkDshNuPackage { inherit pkgs dsh; }` and
 passes the result to `withPlugins`; `flake.lock` pins both inputs. `dsh.withPlugins` wraps the
@@ -79,6 +83,6 @@ Verify after a switch:
 ```sh
 dsh --profile web --dump-config | grep -n "nu-executor\|nu-teaching"
 # expect the first-party shell rows disabled, nu-executor and nu-teaching inserted
-dsh --profile web 2>&1 | grep "disabling profile plugin"
+dsh --profile web o+e>| grep "disabling profile plugin"
 # a dsh bump can disable a row whose manifest no longer matches; nothing prints when healthy
 ```