fix(government): make capability statement a downloadable PDF

[tcconnally]

Summary

• reduce the government route to a short orientation page instead of treating the HTML page as the sendable statement
• add a generated, current one-page federal capability statement PDF
• make every Download capability statement action point to that same-origin PDF with a download filename
• preserve the current claims registry and route Cyber & Networks as the primary mission fit

Verification

• targeted claims/evidence/download tests: 17 passed
• PDF: one Letter page, %PDF-1.4, current metrics and identifiers present, stale 55-MCP/JCP language absent
• local HTTP: government pages returned 200 and the PDF returned application/pdf
• PDF text blocks: no out-of-bounds content

Deployment

The live Pages site remains unchanged until this PR is reviewed and merged; after merge, verify the public HTML and PDF response directly.