feat: installer/bootstrap should not embed hardcoded @perseus version in context.md template

[tcconnally]

Problem

When install_chief_of_staff.sh (or any bootstrapper) writes a baseline context.md, it embeds a hardcoded @perseus vX.Y.Z version string. After Perseus upgrades, this version string goes stale and does not match the installed version.

Expected behavior

The @perseus directive version should either:

1. Be auto-populated at render time from the installed Perseus version (preferred), or
2. Be documented as "update this after upgrading" with a perseus doctor warning when it mismatches the installed version.

Current impact

SAMs who installed before v1.0.10 have @perseus v1.0.8 in their context.md even after upgrading. The directive is cosmetic today but will become load-bearing if Perseus uses it for feature gating.