docs: record responsive header rollout

docs/verification.md

@@ -460,8 +460,10 @@ this verification window.
 
 ## Final full-stack regression
 
-The final application source under test was commit `c6aa3d1`; the later
-documentation-only commit does not alter the tested runtime.
+The broad pre-production regression below tested application commit `c6aa3d1`.
+The later responsive-header follow-up at `768d63a` was separately subjected to
+the complete quality and browser suites, deployed, and verified as recorded
+after this section.
 
 - `./scripts/quality.sh` passed the complete static, formatting, compiler,
   xref, Credo, Sobelow, Dialyzer, dependency-audit, manifest, secret, and image
@@ -556,6 +558,39 @@ documentation-only commit does not alter the tested runtime.
   runtime directories. The reusable ordinary public Compose project and the
   project-owned kind cluster intentionally remain running.
 
+## Responsive-header follow-up
+
+Commit `768d63a` replaced the duplicated public navigation bars with one
+responsive application header. At widths below 1280 px it exposes the primary
+links, language selection, theme controls, and authentication actions through a
+single native `details` menu; wider layouts show the same actions inline.
+
+- `./scripts/quality.sh` passed after the change, including 172 ExUnit tests,
+  formatting, compiler, xref, Credo, Sobelow, Dialyzer, dependency audits,
+  Compose/Helm validation, and gated image scans. Evidence is
+  `output/regression/header-unification-quality-20260719.log`.
+- The isolated browser project passed bootstrap 1/1 and 27/27 scenarios across
+  Chromium, Firefox, and WebKit. Its responsive accessibility case exercised
+  widths 360, 768, 1030, and 1440 px, asserted a single header and primary
+  navigation, and detected no horizontal overflow. Evidence is
+  `output/e2e/20260719174824-537439`.
+- Before the public Compose rollout, the database was backed up to mode-`0600`
+  `output/backups/compose-before-header-20260719-175353.dump` with SHA-256
+  `fea893340d2428a61ebed8abb83816a6273b1afeb5d794763b00c81a37d15e2d`.
+  The archive passed an isolated restore with 23 readable public tables, 1,488
+  rows, all 10 migrations, and PostGIS 3.6.4 before the temporary restore
+  database was removed.
+- The deployed image ID is
+  `sha256:8c3790e6b5fdd3f1feb08165d33d5b2ddaa9089b6606da44a804c5facd4765f6`
+  on 2 healthy web and 2 running worker replicas. The before/after database
+  snapshots were byte-identical: 2 users, 1 request, 7 messages, 4 tracking
+  sessions, and 10 migrations.
+- Public HTTPS and `/healthz/ready` returned HTTP 200. The four BEAM replicas
+  were connected and the deployment's cross-node PubSub check passed. Headed
+  Chrome then verified the public page at 1030 and 360 px: one visible header,
+  accessible menu contents, no horizontal overflow, and zero console errors or
+  warnings. The visible browser was left open at 1030 px with the menu closed.
+
 ## Known work before a public production launch
 
 - Replace the temporary staging origin with the production-owned domain and