feat(agent-presets): rename the two-tool preset to minimal

`core-web` said neither of the things that matter about it. The `-web`
suffix is a leftover from the whole-process `core-web.cordis.yml` overlay,
and presets are per-session and not web-specific. `core` reads as "the
foundational one" when it is in fact the one with the fewest capabilities.

`minimal` says what it is and orders the shipped set legibly by capability:
minimal, standard, cordis.

Breaking: a session created under `core-web` records that id in its header
and will fail to resolve it on resume. Nothing outside this repository has
shipped, so no migration path is offered.

The identically named `config/core-web.cordis.yml` — the legacy
whole-process overlay behind the web snapshot test — is a different thing
and keeps its name.

apps/cli/config/agent-presets/minimal/agent.cordis.yml

@@ -0,0 +1,36 @@
+# The `minimal` agent preset: the two-tool benchmark surface.
+#
+# The native model surface is exactly persistent `bash` plus
+# `str_replace_editor`. Everything else a session could reach — skills, goals,
+# plan mode, delegation, workflows, todo, web — is simply absent rather than
+# disabled, because a preset composes what an agent has instead of subtracting
+# from a shared default.
+#
+# The host composition is unchanged: this agent still runs inside the same
+# sandbox, approval, persistence, and model routing as any other session.
+
+- id: persona
+  name: '@deepseek-ai/dsh-persona'
+  config:
+    text: >-
+      You are a coding agent powered by the {{model}} model. Your working directory is {{cwd}}.
+
+# `tool-bash` provides the `bashEnv` service, so it needs a realm even alone.
+- id: shell
+  name: cordis:group
+  group: true
+  isolate:
+    bashEnv: true
+  config:
+    # The registry and its consumer share the realm: a consumer left outside
+    # would resolve the host's `bashEnv`, which this plane no longer provides.
+    - id: bash-env
+      name: '@deepseek-ai/dsh-bash-env'
+
+    - id: tool-bash
+      name: '@deepseek-ai/dsh-tool-bash'
+
+- id: tool-str-replace-editor
+  name: '@deepseek-ai/dsh-tool-str-replace-editor'
+  config:
+    maxOutputChars: 16000

apps/cli/config/agent-presets/minimal/preset.yml

@@ -0,0 +1,2 @@
+name: 极简模式
+description: 只向模型呈现 bash 与 str_replace_editor，适合 benchmark 与最小复现。