feat: add Grant Writer agent to Specialized Division

[epowelljr]

Summary

Adds a Grant Writer (specialized/grant-writer.md) to the Specialized Division — a comprehensive grant writing specialist for nonprofits, research institutions, and social enterprises covering prospect research, letter of inquiry writing, full proposal development, federal grant compliance, budget narratives, and post-award reporting.

The Agency has no representation for nonprofit or research funding workflows. Grant writing is a highly structured, high-stakes discipline with distinct deliverables at every stage — and it serves one of the largest organizational segments in the US (1.5M+ nonprofits, thousands of academic institutions).

Key capabilities:

• Funder prospect research template: giving profile, alignment assessment, relationship status, logistics
• LOI framework: 5-paragraph structure with hook, solution, track record, ask, and close — under 3 pages
• Full proposal framework: 7-section structure from executive summary through sustainability plan with a logic model integration
• Budget narrative framework: personnel, fringe, consultants, indirect costs, match/cost share — all with calculation templates
• Federal grant compliance checklist: SAM.gov, NOFO compliance, 2 CFR Part 200 allowable costs, attachment requirements
• Post-award reporting framework: progress, outcomes, financial reconciliation, and next period planning
• Win rate targets: ≥35% foundation, ≥20% federal — with rejection analysis built into the workflow

Why this fills a gap: Nonprofits, universities, hospitals, and research institutions collectively represent hundreds of billions in annual grant activity. Grant writing is a specialized skill with a clear, deliverable-focused workflow — exactly the kind of domain the Agency excels at.

Test plan

• Verify frontmatter fields match the existing agent format
• Confirm the agent produces a compliant LOI structure when given a program description and funder guidelines
• Verify the budget narrative shows explicit calculations for every line item
• Check that federal proposals trigger SAM.gov and 2 CFR Part 200 compliance requirements
• Confirm post-award reports include both outcome data and financial reconciliation

cc @msitarzewski — happy to adjust scope, naming, or formatting to match your conventions before merge.