Vendor the ASN.1 modules the codecs are verified against; untrack IDE churn

asn1/
Three tests assert exact bytes - CamEncodeGoldenTest, DenmAirReceiveTest and
SpatemUperCodecTest - and their expected values came from asn1tools compiled
against ETSI modules that existed only as an untracked working copy on one
machine. A golden-byte fixture nobody else can regenerate is a fixture nobody
can safely touch, so the modules are now in the repo.

Only the seven .asn files those tests need are copied, 576 KB of a 4.2 MB
checkout; the upstream Rust parser is not used by this project at all. Verified
sufficient in isolation: copied into an empty directory, all three specs compile
and reproduce the committed golden CAM bytes byte-identically.

Source is consider it GmbH's C-ITS-Parser (github.com/consider-it/C-ITS-Parser)
at f457426, MIT licensed - LICENSE is retained alongside as that requires. The
schemas themselves are ETSI's standard definitions; upstream's contribution is
assembling them into a compilable set. asn1/README.md records the provenance,
which module pairs with which message, and the rule that matters: never
regenerate a golden fixture from this project's own encoder, because sharing a
mistake between encoder and decoder is exactly the failure these files exist to
catch.

Doc references in the codecs and tests now point at asn1/ instead of the
untracked checkout, and C-ITS-Parser/ is gitignored so the working copy beside
the project is never picked up.

Untracked local state
- .idea/deploymentTargetSelector.xml rewrites itself on every deploy, so it has
  been showing as modified in essentially every commit. Along with
  deviceManager.xml, appInsightsSettings.xml and studiobot.xml it is per-machine
  state, not project configuration.
- obu-firmware/sdkconfig.old is ESP-IDF build output - it is the previous
  sdkconfig, rewritten on every build. sdkconfig.defaults remains tracked, since
  that is the configuration actually chosen.

All five stay on disk; only the tracking is removed. Also ignores
.claude/settings.local.json, which is per-machine, while leaving the skills
beside it committable as project knowledge.

app/src/main/java/com/hawhamburg/micr0bu/domain/asn1/CamUperCodec.kt

@@ -262,7 +262,7 @@ object CamUperCodec {
         // Optional-presence bitmap for BasicVehicleContainerHighFrequency's 7 trailing OPTIONAL
         // fields: accelerationControl, lanePosition, steeringWheelAngle, lateralAcceleration,
         // verticalAcceleration, performanceClass, cenDsrcTollingZone (see
-        // C-ITS-Parser/autogen/asn.1/cam_1_4_1.asn).
+        // asn1/cam_1_4_1.asn).
         //
         // Consumed but not acted on, and that is correct: UPER writes a SEQUENCE's presence
         // bitmap up front but each field's VALUE in declaration order, and all seven of these are
@@ -315,7 +315,7 @@ object CamUperCodec {
         // IMPORTANT: if a future change needs any of those - path history is the likely one - the
         // 7 optionals must be parsed and consumed first, in declaration order, or every read after
         // them lands at the wrong bit offset. At that point this hand-written decoder stops being
-        // the right tool; use the generated codec (see C-ITS-Parser) instead.
+        // the right tool; use a generated codec (see asn1/README.md) instead.
         return Cam(
             stationId = stationId,
             stationType = stationType,

app/src/main/java/com/hawhamburg/micr0bu/domain/asn1/DenmUperCodec.kt

@@ -18,8 +18,7 @@ import com.hawhamburg.micr0bu.domain.denm.DenmEvent
  * large, deeply nested, and nothing consumes them yet.
  *
  * ## Field widths
- * Every width below is taken from the ETSI ASN.1 modules in the `C-ITS-Parser` checkout
- * (`autogen/asn.1/denm_1_3_1.asn`, `cdd_1_3_1_1.asn`), and every extension marker was
+ * Every width below is taken from the ETSI ASN.1 modules in `asn1/` (`denm_1_3_1.asn`, `cdd_1_3_1_1.asn`), and every extension marker was
  * cross-checked against how `rasn` renders the same type (`#[non_exhaustive]` marks an extensible
  * SEQUENCE). That cross-check matters: hand-derived widths are exactly how this project shipped a
  * one-bit `CurvatureCalculationMode` bug in CAM that was invisible until measured against real

app/src/main/java/com/hawhamburg/micr0bu/domain/asn1/SpatemUperCodec.kt

@@ -13,8 +13,7 @@ import com.hawhamburg.micr0bu.domain.spat.SpatEvent
  * Decode-only: this project never transmits SPATEM, that is an RSU's job.
  *
  * ## Field widths
- * Every width is taken from the ETSI ASN.1 modules in the `C-ITS-Parser` checkout
- * (`dsrc_2_2_1.asn`, `cdd_2_2_1.asn`):
+ * Every width is taken from the ETSI ASN.1 modules in `asn1/` (`dsrc_2_2_1.asn`, `cdd_2_2_1.asn`):
  *
  *  - `MinuteOfTheYear` (0..527040) = 20 bits
  *  - `DSecond` (0..65535) = 16 bits