Android comments describe the code to a stranger (#6223)

Milestone 546 "Bring the repo to the comment standard (rule 32) and
compose defaults (rule 198)", step #6223 "Comment standard sweep:
Android client".

KDoc, comments, manifest and resource notes, Gradle and TOML comments
and the ffi crate's docs now state what the code does and the
non-obvious why in the present tense. Issue, Scribe-note, milestone
(M13, M304, M315, M12) and family-idea references are gone, as are
comparisons to Minstrel and the narration of what used to be: the
capture sheet the editor replaced, the per-note colour story, the
operator's device-pass feedback, the bindgen-as-[[bin]] failure, the
0.60 edge alpha before it was re-solved, and the checker bugs behind
check-strings/check-symbols. Hazards stay as facts: the signing key that
can't be rotated, the alias that keeps the earlier name, PKCS12's single
password, unwind over abort, the UTC date-picker read, the
DerivedTint/colors.ts mirror.

One stale claim is gone: DerivedTint said the web had no test runner,
but notes/grammar.test.ts runs the same tint cases. detekt.yml said
"these two places" over a list of five.

49 files, comments only: a comment-stripping diff of every changed file
against HEAD is identical.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

android/gradle/libs.versions.toml

@@ -1,5 +1,5 @@
 [versions]
-# Pinned as a MATRIX, matching Minstrel's proven combination on the same JDK:
+# Pinned as a MATRIX:
 #   - Gradle 9.1.0 supports JDK 25 (see gradle-wrapper.properties)
 #   - AGP 9.0.1 requires Gradle 9.1.0+
 #   - Kotlin 2.3.x is AGP 9's built-in Kotlin path
@@ -14,16 +14,13 @@ coroutines = "1.9.0"
 
 # WorkManager runs the background sync. `work-runtime-ktx` is NOT used: as of
 # 2.11 it is a 6 KB stub and every Kotlin extension (`PeriodicWorkRequestBuilder`,
-# `CoroutineWorker`) has moved into `work-runtime` itself. Verified by unpacking
-# both artifacts, not from memory.
+# `CoroutineWorker`) has moved into `work-runtime` itself.
 work = "2.11.2"
 
-# ktlint and detekt are NOT Gradle plugins here. ci-rust-android already ships
-# both as pinned CLIs (M12 step 3), and the CI lane invokes those directly. Adding
-# the Gradle plugins would mean a SECOND pinned version of each tool, resolved at
-# build time, that has to be kept in lockstep with the image's by hand — and the
-# first attempt at it failed outright, because the detekt version Minstrel pins
-# (2.0.0-alpha.3) is not published to Maven Central or the plugin portal at all.
+# ktlint and detekt are NOT Gradle plugins here. ci-rust-android ships both as
+# pinned CLIs, and the CI lane invokes those directly. The Gradle plugins would be
+# a SECOND pinned version of each tool, resolved at build time, that has to be
+# kept in lockstep with the image's by hand.
 
 # JNA is not optional: uniffi's Kotlin bindings call into the .so through it.
 # The @aar classifier matters — the plain jar has no Android native payload and
@@ -32,7 +29,7 @@ jna = "5.14.0"
 
 junit = "4.13.2"
 
-# Coil draws a link preview's image (Scribe #3307), the first image this client
+# Coil draws a link preview's image, the first image this client
 # loads. Coil 3 ships its networking separately; the OkHttp fetcher is the one its
 # docs name as the default, and it registers itself, so no loader is configured.
 # Held at 3.5.0: 3.6.0 moved to compileSdk 37 and Compose 1.12, which need AGP 9.1.