refactor: rename RoleDefinition fields for clarity

- identity → goal
- prepare → capabilities (string[])
- execute → procedure
- report → output
- outputSchema → meta

Fixes #364

examples/analyze-topic.yaml

@@ -3,22 +3,23 @@ description: "Single-role topic analysis using four-phase role description"
 roles:
   analyst:
     description: "Analyzes a given topic and produces a structured summary"
-    identity: |
+    goal: |
       You are a research analyst with expertise in breaking down complex topics
       into clear, structured summaries. You think critically and cite key points.
-    prepare: |
-      Review the topic carefully. Consider multiple perspectives and identify
-      the core question being asked.
-    execute: |
+    capabilities:
+      - research
+      - critical-thinking
+      - structured-writing
+    procedure: |
       Analyze the topic by:
       1. Identifying the main thesis or question
       2. Listing 3-5 key points with brief explanations
       3. Noting any counterarguments or caveats
       Keep your analysis concise (under 500 words).
-    report: |
+    output: |
       Provide your analysis as markdown under the frontmatter.
       The frontmatter must include your structured findings.
-    outputSchema:
+    meta:
       type: object
       properties:
         thesis:

examples/solve-issue.yaml

@@ -3,11 +3,13 @@ description: "End-to-end issue resolution"
 roles:
   planner:
     description: "Creates implementation plan"
-    identity: "You are a planning agent. You analyze issues and create step-by-step plans."
-    prepare: "Read the issue description and any linked context carefully."
-    execute: "Analyze the issue and create a detailed, actionable implementation plan."
-    report: "Output the plan summary and list of concrete steps."
-    outputSchema:
+    goal: "You are a planning agent. You analyze issues and create step-by-step plans."
+    capabilities:
+      - issue-analysis
+      - planning
+    procedure: "Analyze the issue and create a detailed, actionable implementation plan."
+    output: "Output the plan summary and list of concrete steps."
+    meta:
       type: object
       properties:
         plan:
@@ -19,11 +21,14 @@ roles:
       required: [plan, steps]
   developer:
     description: "Implements code changes"
-    identity: "You are a developer agent. You implement code changes according to plans."
-    prepare: "Load coding tools and review the project structure and conventions."
-    execute: "Implement the plan. Write code, tests, and ensure existing tests pass."
-    report: "List all files changed and provide a summary of the implementation."
-    outputSchema:
+    goal: "You are a developer agent. You implement code changes according to plans."
+    capabilities:
+      - file-edit
+      - shell
+      - testing
+    procedure: "Implement the plan. Write code, tests, and ensure existing tests pass."
+    output: "List all files changed and provide a summary of the implementation."
+    meta:
       type: object
       properties:
         filesChanged:
@@ -35,11 +40,13 @@ roles:
       required: [filesChanged, summary]
   reviewer:
     description: "Reviews code changes"
-    identity: "You are a code reviewer. You review implementations for correctness and quality."
-    prepare: "Review the project's coding standards and conventions."
-    execute: "Review the implementation against the plan. Check for bugs, edge cases, and style."
-    report: "Approve or reject with detailed comments explaining your decision."
-    outputSchema:
+    goal: "You are a code reviewer. You review implementations for correctness and quality."
+    capabilities:
+      - code-review
+      - static-analysis
+    procedure: "Review the implementation against the plan. Check for bugs, edge cases, and style."
+    output: "Approve or reject with detailed comments explaining your decision."
+    meta:
       type: object
       properties:
         approved: