Format last three markdown files; cap billsplit's Android build memory

Brings the repo to prettier-clean across all 525 tracked md/json/yaml files.
The markdown edits are cosmetic: escaping `L*` so it stops rendering as
emphasis, normalising `*em*` to `_em_`, and aligning tables.

billsplit/android/gradle.properties shipped from the Flutter template asking
for `-Xmx8G -XX:MaxMetaspaceSize=4G` — more than this machine has. Lowered to
768m/512m and, more importantly, cut the number of JVMs: Kotlin compiles
in-process, no persistent daemon, no parallel execution, one worker.

Also repairs a regression an earlier prettier pass introduced. That pass
pretty-printed test/fixtures/sample_receipt.json, but
`accepts bare JPK payload and bare JWS token` reads the fixture as raw TEXT
with a regex matching `"data":"..."` with no space after the colon. The
inserted space made the match null and the null-check operator threw.
Comparing the parsed JSON for equality had passed and proved nothing about
that raw-text contract.

The fixture is restored to its original minified bytes — a real e-paragon
arrives as single-line JSON — and test/fixtures/ is now in .prettierignore so
captured payloads stay byte-faithful. The regex also tolerates whitespace now
and asserts the match is non-null with a reason, so the same change would fail
readably instead of crashing. Verified against both the minified and the
pretty-printed fixture.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

billsplit/android/gradle.properties

@@ -1,6 +1,24 @@
-org.gradle.jvmargs=-Xmx8G -XX:MaxMetaspaceSize=4G -XX:ReservedCodeCacheSize=512m -XX:+HeapDumpOnOutOfMemoryError
+# Memory budget. The Flutter template ships `-Xmx8G -XX:MaxMetaspaceSize=4G`
+# here, which asks for more than this 7.6 GB machine has and got a whole
+# session OOM-killed. What actually brings the footprint down is cutting the
+# NUMBER of JVMs, not just the heap: without these flags Gradle runs a daemon
+# plus a separate Kotlin compile daemon plus workers, each with its own heap.
+#
+# Budget for anything run on this machine is <= 2 GB. Verify with PSS summed
+# from /proc/<pid>/smaps_rollup across the build's own processes — system-wide
+# "used" includes everything else, and RSS double-counts shared pages.
+org.gradle.jvmargs=-Xmx768m -XX:MaxMetaspaceSize=512m -XX:ReservedCodeCacheSize=128m -XX:+HeapDumpOnOutOfMemoryError
+# Compile Kotlin inside the Gradle process instead of spawning a second daemon.
+kotlin.compiler.execution.strategy=in-process
+# No persistent daemon, no parallel project execution, one worker.
+org.gradle.daemon=false
+org.gradle.parallel=false
+org.gradle.workers.max=1
+
 android.useAndroidX=true
 # This newDsl flag was added by the Flutter template
 android.newDsl=false
-# This builtInKotlin flag was added by the Flutter template
+# This builtInKotlin flag was added by the Flutter template. Kept false to
+# match every sibling app (todo, habit_stack, home_inventory, diet_guard_app),
+# which all build fine on this same AGP 9.0.1 / Gradle 9.1.0 pair.
 android.builtInKotlin=false

billsplit/test/eparagon_parser_test.dart

@@ -63,8 +63,12 @@ void main() {
   test('accepts bare JPK payload and bare JWS token', () {
     final res = parseEParagonDetailed(fixture);
     expect(res.receipt.items, isNotEmpty);
-    // Raw JWS from the wrapper should parse identically.
-    final jws = RegExp('"data":"([^"]+)"').firstMatch(fixture)!.group(1)!;
+    // Raw JWS from the wrapper should parse identically. Tolerate whitespace
+    // around the colon: the fixture is minified as the device emits it, but a
+    // pretty-printed payload is equally valid JSON and must not fail here.
+    final match = RegExp(r'"data"\s*:\s*"([^"]+)"').firstMatch(fixture);
+    expect(match, isNotNull, reason: 'fixture must carry a "data" JWS field');
+    final jws = match!.group(1)!;
     final fromJws = parseEParagon(jws);
     expect(fromJws.items.length, res.receipt.items.length);
   });