feat: add uwf skill cli command and Prepare section in role prompt

- Add 'uwf skill cli' command that prints markdown CLI reference
- buildRolePrompt now generates ## Prepare section:
  - Always prompts agent to run 'uwf skill cli' (explicit skill)
  - Renders capabilities as keyword hints for implicit skill loading

Fixes #369

packages/cli-workflow/src/cli.ts

@@ -14,6 +14,7 @@ import {
   cmdCasWalk,
 } from "./commands/cas.js";
 import { cmdSetup, cmdSetupInteractive } from "./commands/setup.js";
+import { cmdSkillCli } from "./commands/skill.js";
 import {
   cmdThreadFork,
   cmdThreadKill,
@@ -220,6 +221,15 @@ thread
     });
   });
 
+const skill = program.command("skill").description("Built-in skill references for agents");
+
+skill
+  .command("cli")
+  .description("Print a markdown reference of all uwf commands")
+  .action(() => {
+    console.log(cmdSkillCli());
+  });
+
 program
   .command("setup")
   .description("Configure provider, model, and agent")

packages/cli-workflow/src/commands/skill.ts

@@ -0,0 +1,70 @@
+export function cmdSkillCli(): string {
+  return `# uwf CLI Reference
+
+## Setup
+
+\`\`\`
+uwf setup                                         # interactive setup wizard
+uwf setup --provider <name> --base-url <url> \\
+           --api-key <key> --model <name>          # non-interactive setup
+           [--agent <name>]                        # optional: default agent alias
+\`\`\`
+
+## Workflow Commands
+
+\`\`\`
+uwf workflow put <file>           # register a workflow from YAML file
+uwf workflow show <id>            # show workflow by name or CAS hash
+uwf workflow list                 # list all registered workflows
+\`\`\`
+
+## Thread Commands
+
+\`\`\`
+uwf thread start <workflow> -p <prompt>           # create a thread (no execution)
+uwf thread step <thread-id>                       # execute one moderator→agent→extract cycle
+               [--agent <cmd>]                    # override agent command
+uwf thread show <thread-id>                       # show thread head pointer
+uwf thread list                                   # list active threads
+               [--all]                            # include archived threads
+uwf thread kill <thread-id>                       # terminate and archive a thread
+uwf thread steps <thread-id>                      # list all steps in a thread
+uwf thread read <thread-id>                       # render thread context as markdown
+               [--quota <chars>]                  # max output characters (default 32000)
+               [--before <step-hash>]             # load steps before this hash (exclusive)
+               [--start]                          # include start step in output
+uwf thread fork <step-hash>                       # fork a thread from a specific step
+uwf thread step-details <step-hash>               # dump full detail node of a step as YAML
+\`\`\`
+
+## CAS Commands
+
+\`\`\`
+uwf cas get <hash>                # read a CAS node (type + payload)
+            [--timestamp]         # include timestamp in output
+uwf cas put <type-hash> <data>    # store a node, print its hash
+                                  # <data>: JSON file path or inline JSON string
+uwf cas has <hash>                # check if a hash exists
+uwf cas refs <hash>               # list direct CAS references from a node
+uwf cas walk <hash>               # recursive traversal from a node
+uwf cas reindex                   # rebuild type index from all CAS nodes
+uwf cas schema list               # list all registered schemas
+uwf cas schema get <hash>         # show a schema by its type hash
+\`\`\`
+
+## Global Options
+
+\`\`\`
+uwf --format <fmt>                # output format: json (default) or yaml
+uwf -V, --version                 # print version
+\`\`\`
+
+## Key Concepts
+
+- **Workflow**: YAML definition with roles, conditions, and a routing graph; stored as a CAS node identified by its XXH64 hash.
+- **Thread**: A single workflow execution (ULID). State is an immutable CAS chain; active threads are indexed in \`threads.yaml\`.
+- **Step**: One moderator→agent→extract cycle. Run \`uwf thread step\` repeatedly until \`$END\`.
+- **CAS**: Content-Addressed Storage — all nodes are immutable and identified by hash.
+- **Role**: Named actor with a system prompt and JSON Schema output; the moderator routes between roles.
+`;
+}

packages/workflow-agent-kit/__tests__/build-role-prompt.test.ts

@@ -18,13 +18,16 @@ describe("buildRolePrompt", () => {
     expect(result).toContain("## Capabilities");
     expect(result).toContain("- cursor-agent");
     expect(result).toContain("- file-edit");
+    expect(result).toContain("## Prepare");
+    expect(result).toContain("uwf skill cli");
+    expect(result).toContain("cursor-agent, file-edit");
     expect(result).toContain("## Procedure");
     expect(result).toContain("Implement the feature.");
     expect(result).toContain("## Output");
     expect(result).toContain("Summarize changes.");
   });
 
-  test("empty fields are omitted", () => {
+  test("empty fields are omitted but Prepare is always present", () => {
     const role: RoleDefinition = {
       description: "A reviewer",
       goal: "You are a code reviewer.",
@@ -35,12 +38,14 @@ describe("buildRolePrompt", () => {
     };
     const result = buildRolePrompt(role);
     expect(result).toContain("## Goal");
+    expect(result).toContain("## Prepare");
+    expect(result).toContain("uwf skill cli");
     expect(result).toContain("## Procedure");
     expect(result).not.toContain("## Capabilities");
     expect(result).not.toContain("## Output");
   });
 
-  test("all empty returns empty string", () => {
+  test("all empty still includes Prepare section", () => {
     const role: RoleDefinition = {
       description: "Minimal",
       goal: "",
@@ -50,7 +55,12 @@ describe("buildRolePrompt", () => {
       meta: "placeholder00000" as string,
     };
     const result = buildRolePrompt(role);
-    expect(result).toBe("");
+    expect(result).toContain("## Prepare");
+    expect(result).toContain("uwf skill cli");
+    expect(result).not.toContain("## Goal");
+    expect(result).not.toContain("## Capabilities");
+    expect(result).not.toContain("## Procedure");
+    expect(result).not.toContain("## Output");
   });
 
   test("capabilities rendered as bullet list", () => {

packages/workflow-agent-kit/src/build-role-prompt.ts

@@ -3,8 +3,12 @@ import type { RoleDefinition } from "@uncaged/workflow-protocol";
 /**
  * Build the role prompt from a RoleDefinition.
  *
- * Assembles structured sections: Goal, Capabilities, Procedure, Output.
+ * Assembles structured sections: Goal, Capabilities, Prepare, Procedure, Output.
  * Empty strings and empty arrays are omitted from the output.
+ *
+ * The Prepare section always instructs the agent to run `uwf skill cli` to load
+ * workflow knowledge, plus renders the capabilities array as keyword hints for
+ * implicit skill loading.
  */
 export function buildRolePrompt(role: RoleDefinition): string {
   const sections: string[] = [];
@@ -18,6 +22,22 @@ export function buildRolePrompt(role: RoleDefinition): string {
     sections.push(`## Capabilities\n\n${list}`);
   }
 
+  const prepareLines: string[] = [
+    "Run the following command to load workflow CLI knowledge before starting work:",
+    "",
+    "```",
+    "uwf skill cli",
+    "```",
+  ];
+  if (role.capabilities.length > 0) {
+    const keywords = role.capabilities.join(", ");
+    prepareLines.push(
+      "",
+      `You have the following capabilities: ${keywords}. Load relevant skills matching these keywords before starting work.`,
+    );
+  }
+  sections.push(`## Prepare\n\n${prepareLines.join("\n")}`);
+
   if (role.procedure !== "") {
     sections.push(`## Procedure\n\n${role.procedure}`);
   }