docs: convert all architecture .adoc sections to markdown, prettier-format all .md

- Converted 13 individual .adoc section files to .md via
  asciidoctor→docbook5→pandoc(gfm) + post-processing, placed alongside
  the .adoc sources in Docs/Architecture/
- Rebuilt architecture.md from the individual section .md files
- Ran prettier --write on all .md in the repo (23 files changed):
  normalised table column alignment, trailing whitespace, line breaks
- Added .agents/ to .prettierignore (vendored third-party content)
- All .md now passes prettier --check

Geo/verification/2026-11-06-street-profile.md

@@ -30,7 +30,7 @@ Crossing endpoints sit within about 1 m of the kerb line, so these lengths appro
 Mapped sidewalk centrelines sit **12.6 m** (south) and **13.6 m** (north) from the road centreline. Building setbacks, measured to each building's nearest vertex:
 
 | Side | Building | Setback | Frontage extent |
-| --- | --- | ---: | ---: |
+| --- | --- | --: | --: |
 | S | 6922 | 14.6 m | 66.1 m |
 | S | 6902 | 14.5 m | 31.0 m |
 | S | **6840 El Capitan Entertainment Centre** | **14.5 m** | **25.7 m** |