Fix broken v2 bambulab schema refs, wire up v2 dispatchers, fix PrintJobStatus JSON mismatch

- v2/common/device/device.schema.json: stray backtick in bed $ref broke resolution
- v2/report/print/print.schema.json: ams $ref pointed at wrong path (missing ams/ subdir)
- v2/common/device/plate.schema.json: $id was copy-pasted from bed.schema.json
- Add v2/request.schema.json and v2/report.schema.json dispatchers - v2's leaf
  schemas were unreachable without them, same oneOf convention as v1
- Rewrite schemas/bambulab/README.md layout section, which still described
  v1's pre-rename paths and claimed v2 was removed
- PrintJob.status serialized as a raw i32 in Rust (prost stores proto3 enums
  as i32) while ts-types' TypeBox schema validates full enum name strings -
  add serde with= on the field so Rust JSON matches TS and protobuf's own
  canonical JSON enum mapping, plus a regression test

schemas/bambulab/v2/report/print/print.schema.json

@@ -12,7 +12,7 @@
 
         "2D": { "$ref": "./_2d_report.schema.json" },
         "3D": { "$ref": "./_3d_report.schema.json" },
-        "ams": { "$ref": "../../common/ams.schema.json" },
+        "ams": { "$ref": "../../common/ams/ams.schema.json" },
         "hms": { "$ref": "../../common/hms.schema.json" },
         "lights_report": { "$ref": "../../common/lights_report.schema.json" },
         "upgrade_state": { "$ref": "../../common/upgrade_state.schema.json" },