[P1-b] Add argument-hint to argument-accepting skills

[JeremyDev87]

Parent: #731

Purpose

Add argument-hint to skills that accept arguments so users can intuitively see what arguments to pass during / autocomplete.

v2.0 Rule

argument-hint: Hint shown during autocomplete to indicate expected arguments. Example: [issue-number] or [filename] [format].

Target Files (6 files)

1. packages/rules/.ai-rules/skills/pr-all-in-one/SKILL.md

argument-hint: [target-branch] [issue-id]

Rationale: Usage section in SKILL.md body already defines /pr-all-in-one [target-branch] [issue-id] format

2. packages/rules/.ai-rules/skills/pr-review/SKILL.md

argument-hint: [pr-url-or-number]

Rationale: Accepts PR number or URL as argument to determine review target

3. packages/rules/.ai-rules/skills/code-explanation/SKILL.md

argument-hint: [file-or-symbol]

Rationale: Specifies the file or symbol to explain

4. packages/rules/.ai-rules/skills/mcp-builder/SKILL.md

argument-hint: [capability-name]

Rationale: Specifies the MCP capability (tool/resource/prompt) name to create

5. packages/rules/.ai-rules/skills/security-audit/SKILL.md

argument-hint: [scope-or-path]

Rationale: Specifies the audit target scope or path

6. packages/rules/.ai-rules/skills/legacy-modernization/SKILL.md

argument-hint: [target-module-or-path]

Rationale: Specifies the target module or path for modernization

How to Apply

Add the argument-hint field inside the YAML frontmatter (--- block) of each file.

Acceptance Criteria

• All 6 files have argument-hint added
• Hints match the usage described in the skill body
• No YAML frontmatter syntax errors
• No changes to existing fields or skill body