fix(release): repair functions.php + ARCHITECTURE.md truncations from prior commit

The prior commit (4a506e1c) was assembled from a sandbox bash mount that
returned a truncated view of two files. Net effect:
  - functions.php was cut at line 235, dropping the closing of
    peptide_starter_inline_dark_mode_script() and its add_action
    registration. wp_head dark-mode script was effectively removed.
  - ARCHITECTURE.md was cut mid-paragraph and lost its Version section.

Both files are now rebuilt from main + minimum-delta patches:
  - functions.php: +4 minimal additions (perf-asset-policy @see, version
    bump, require_once, add_action). Dark-mode script preserved.
  - ARCHITECTURE.md: +3 lines (perf-asset-policy in inc/ tree, version
    banner bumped). Version section preserved.
  - style.css, CHANGELOG.md, CONVENTIONS.md: also rebuilt from main +
    targeted patches as a safety measure (no functional change vs the
    prior commit, just guaranteed-untruncated).

Verified: every file ends with a trailing newline; functions.php contains
the dark-mode add_action; ARCHITECTURE.md contains the Version section.

Co-authored-by: Engineer Theme (in-session subagent) <engineer-theme@peptiderepo.users.noreply.github.com>

ARCHITECTURE.md

@@ -263,4 +263,11 @@ control in the theme.
 
 `inc/cloudflare-ips.php` holds a static snapshot of CF ranges. Refresh
 quarterly. Override via `peptide_starter_cloudflare_ip_ranges` filter
-for out-of-band update
+for out-of-band updates.
+
+## Version
+
+**Current:** v1.6.0 (2026-04-23)
+
+Bump `style.css` header line 7 and `PEPTIDE_STARTER_VERSION` in
+`functions.php` together on release.