feat(agents): rewrite Website Content Strategist Agent for multi-provider support #1099

Summary

Convert the website-content-strategist-agent ChatGPT/Codex export in agents/website-content-strategist-agent/ into a standardised multi-provider agent supporting Claude, GitHub Copilot, and OpenAI Codex, wrapped in the lightspeed-content-strategy plugin. Part of Epic #1079.

Phase: 2

Proposed Solution

Restructure the export into the standard multi-provider layout:

• AGENT.md — agent spec with YAML frontmatter (validated against multi-provider-agent.schema.json)
• shared/core-prompt.md — provider-agnostic core instructions
• claude/, copilot/, openai/ — provider-specific agent.md + tool/skill definitions
• .github/ — INSTALL.md, MANIFEST.json, security-policy.md
• Preserve original skills/, manifests/, checksums.sha256 from the export
• Wrap in the lightspeed-content-strategy plugin (plugin.json + copilot-plugin.json)

Reference pattern: .github/projects/active/agent-standards-initiative/PROMPT_1_PLAYWRIGHT_AGENT_REWRITE.md (pilot) and PROMPT_2_GENERIC_AGENT_REWRITE.md (template).

Acceptance Criteria

• AGENT.md created with valid YAML frontmatter and all required fields
• shared/core-prompt.md created (provider-agnostic)
• Claude, Copilot, and OpenAI provider configs + tool definitions created
• lightspeed-content-strategy plugin manifests created and valid
• Original export data preserved (skills, manifests, checksums)
• Passes agent-spec-validator, multi-provider-consistency-checker, plugin-integrity-checker
• Documentation/changelog updated
• Tests added/updated
• PR uses correct branch prefix (feat/)
• Labels/types match org standards

Designs / References

• Planning package: .github/projects/active/agent-standards-initiative/
• Framework: .github/reports/frameworks/agent-standardization-framework-2026-07-22.md

Dependencies

• Epic Epic: Multi-Provider Agent Standardization Initiative #1079
• Schema, hooks, and instruction infrastructure issues (Phase 1) should land first
• Depends on Phase 1 pilot pattern being merged

Testing Approach

Schema validation of AGENT.md and manifests; hook validation (spec/consistency/integrity); provider config load checks; agent unit test suite.

Additional Context

Target plugin: lightspeed-content-strategy. Source export: agents/website-content-strategist-agent/.

Definition of Ready (DoR)

• Problem statement and outcome defined
• Acceptance criteria written
• Designs/specs/references attached
• Dependencies mapped
• Estimate added (2-4h; pilot 12-18h)
• Stakeholders/approvers listed (LightSpeed maintainers)
• Milestone/iteration assigned

Definition of Done (DoD)

• All acceptance criteria met
• Tests added/updated; CI green
• Accessibility: N/A (agent config) or WCAG 2.2 AA where UI output applies
• Security: no secrets committed; secrets-scanner + agent-security-auditor pass
• Performance: no measurable regression introduced
• Docs/changelog updated
• QA verified/UAT approved (if applicable)
• Release notes prepared

Related issues: #1079