docs(phase6e): document the ROOT Foundations Completion milestone

Adds PHASE6E_ROOT_FOUNDATIONS_COMPLETION.md (the phase's own record: what was authored, the
dash-vs-bash scenario bug found and fixed, the pre-existing lock-enforcement gap found and
fixed, the regression fallout that fix revealed in earlier suites and why each was a stale test
assumption rather than a platform bug, and honest test/rehearsal/regression results).

Updates ROOT_FOUNDATIONS_PILOT_READINESS.md (full re-audit: all 4 ROOT Foundations courses now
READY, not inherited blindly from Phase 6D), ROOT_PROGRAM_DURATION_MODEL.md (real ROOT 02-04
duration data: 24.7 combined hours, landing inside Phase 6D's own estimated range; 67.9 hours
across the full authored program), ROOT_PILOT_CURRICULUM.md (ROOT 02-04 move from NOT IN PILOT
to IN PILOT with full module-level detail; the pilot is now genuinely self-paced-capable for the
entire foundational half, not just instructor-led), ROOT_PROGRAM_ARCHITECTURE.md and
ROOT_CURRICULUM_COVERAGE_MATRIX.md (course/module/scenario totals), and
ROOT_FOUNDATIONS_ARCHITECTURE.md (marked as-built, not just as-designed).

Co-Authored-By: Claude Sonnet 5 <[email protected]>

docs/ROOT_FOUNDATIONS_ARCHITECTURE.md

@@ -7,6 +7,12 @@ activity type or content model was needed. Every course below is a row that alre
 `courses` (`status='planned'`, seeded by Phase 6A's `022_course_content.sql`) — this phase adds
 their modules and activities, and updates their `status`/`objectives`/`prerequisites`.
 
+**Status as of Phase 6E:** this document was written as a DESIGN in Phase 6D, when only ROOT 01
+was actually authored. As of Phase 6E, all four courses below (ROOT 01-04) are fully authored
+and READY exactly as designed here — see `docs/PHASE6E_ROOT_FOUNDATIONS_COMPLETION.md` and
+`docs/ROOT_FOUNDATIONS_PILOT_READINESS.md` for the built/verified state. The module tables below
+remain accurate as the as-built architecture, not just the original plan.
+
 ## Course sequence and prerequisite chain
 
 ```