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.properties

@@ -1,7 +1,7 @@
 # --enable-native-access=ALL-UNNAMED silences the JDK 22+ "restricted method in
 # java.lang.System has been called" warning that Gradle 9.1's bundled
-# native-platform jar trips via System.load(). Same opt-in Minstrel needs on the
-# same Gradle/JDK pair; future JDKs promote the warning to an error.
+# native-platform jar trips via System.load(); future JDKs promote the warning
+# to an error.
 org.gradle.jvmargs=-Xmx4g -Dfile.encoding=UTF-8 --enable-native-access=ALL-UNNAMED
 org.gradle.parallel=true
 org.gradle.caching=true
@@ -9,8 +9,8 @@ org.gradle.configuration-cache=true
 android.useAndroidX=true
 android.nonTransitiveRClass=true
 
-# Matches Minstrel: detekt 2.0-alpha and the ktlint Gradle plugin still have
-# intermittent configuration-cache holes. Warn rather than fail so the CC speedup
-# applies where it can.
+# detekt 2.0-alpha and the ktlint Gradle plugin have intermittent
+# configuration-cache holes. Warn rather than fail so the CC speedup applies
+# where it can.
 org.gradle.configuration-cache.problems=warn
 kotlin.code.style=official