Wire up proto/bambulab/ build pipeline (boilerplate — message bodies TBD)

Adds bambulab/v1 and bambulab/v2 to the prost-build pipeline, scoped
separately from continuum.v1's camelCase convention: bambulab.* uses
snake_case, matching Bambu's actual MQTT wire JSON exactly, since this is
edge-only traffic (continuum-proxy) that has to match the printer's real
format rather than a schema we get to design.

Verified the scoping doesn't collide: type_attribute calls are cumulative,
so the existing '.' blanket selector had to become '.continuum' specifically
- keeping it global would stack a second, conflicting #[serde(rename_all)]
onto every bambulab type too and fail to compile.

No message bodies added - proto/bambulab/{common,v1/*,v2/*}.proto are
intentionally just syntax+package+guidance comments (matching what was
already started for v1). build.rs has inline notes on the two real gotchas
already hit while prototyping this: the field_attribute path-matching
oneof/variant collision (solution: hand-write the envelope enum in Rust
instead of modeling it as a proto oneof), and serde needing #[serde(default)]
on fields that aren't always present.

packages/rust-types/build.rs

@@ -11,6 +11,11 @@ fn main() {
         proto_root.join("continuum/v1/print_params.proto"),
         proto_root.join("continuum/v1/template.proto"),
         proto_root.join("continuum/v1/print_job.proto"),
+        proto_root.join("bambulab/common.proto"),
+        proto_root.join("bambulab/v1/request.proto"),
+        proto_root.join("bambulab/v1/report.proto"),
+        proto_root.join("bambulab/v2/request.proto"),
+        proto_root.join("bambulab/v2/report.proto"),
     ];
 
     for file in &proto_files {
@@ -18,8 +23,41 @@ fn main() {
     }
 
     let mut config = prost_build::Config::new();
-    config.type_attribute(".", "#[derive(serde::Serialize, serde::Deserialize)]");
-    config.type_attribute(".", "#[serde(rename_all = \"camelCase\")]");
+
+    // continuum.v1 — Continuum's own cross-service API. camelCase to match
+    // the TS side's existing convention (this is a schema we designed
+    // ourselves, so we get to pick the convention).
+    config.type_attribute(".continuum", "#[derive(serde::Serialize, serde::Deserialize)]");
+    config.type_attribute(".continuum", "#[serde(rename_all = \"camelCase\")]");
+
+    // bambulab.* — mirrors Bambu's actual MQTT wire JSON exactly
+    // (snake_case), because this isn't a schema we get to design: it's
+    // edge-only traffic (continuum-proxy only, never crosses into TS) that
+    // has to match whatever the printer actually sends, byte for byte.
+    //
+    // IMPORTANT: these two type_attribute calls are scoped to ".bambulab"
+    // specifically, not "." (global) — type_attribute calls are cumulative,
+    // so a "." blanket rule here would stack a second, conflicting
+    // #[serde(rename_all = ...)] onto every bambulab type alongside this
+    // one and fail to compile. Verified: see commit history for this file.
+    config.type_attribute(".bambulab", "#[derive(serde::Serialize, serde::Deserialize)]");
+    config.type_attribute(".bambulab", "#[serde(rename_all = \"snake_case\")]");
+
+    // Some Bambu response fields aren't always present (e.g. `result`/
+    // `reason` on some info responses) — serde requires every struct field
+    // present in the JSON unless told otherwise. Add one line per such
+    // field as you find them, e.g.:
+    //   config.field_attribute(".bambulab.v1.InfoResponse.result", "#[serde(default)]");
+    //
+    // Do NOT try to model the top-level {"info": {...}} / {"pushing": {...}}
+    // envelope as a proto `oneof` here — prost-build's field/variant
+    // attribute matching can't distinguish "the oneof field" from "the
+    // variants inside it" (both match the same path prefix), so
+    // `#[serde(flatten)]` lands in the wrong place and won't compile. Write
+    // the envelope as a plain Rust enum instead, in continuum-proxy —
+    // serde's default enum representation already produces exactly
+    // {"info": {...}} with no configuration at all. See
+    // continuum-proxy/src/printer/bambu_protocol.rs.
 
     config
         .compile_protos(&proto_files, &[proto_root])

proto/bambulab/common.proto

@@ -0,0 +1,9 @@
+syntax = "proto3";
+
+package bambulab;
+
+// Fields/messages genuinely shared between v1 and v2 (unversioned, since
+// they don't change across generations) go here — composition, embedded as
+// a field in v1/v2 messages via `import "bambulab/common.proto";`, not
+// inheritance. e.g. every Bambu command/response shares sequence_id +
+// command; that's a good candidate for a message here.

proto/bambulab/v1/report.proto

@@ -0,0 +1,15 @@
+syntax = "proto3";
+
+package bambulab.v1;
+
+// import "bambulab/common.proto"; once common.proto has a shared message
+// worth embedding (composition, not inheritance — see that file).
+
+// Your report/response messages go here, e.g.:
+//
+// message InfoResponse {
+//   string sequence_id = 1;
+//   string command = 2;
+//   string result = 3;   // not always present — see build.rs field_attribute
+//   string reason = 4;   // not always present — see build.rs field_attribute
+// }

proto/bambulab/v1/request.proto

@@ -0,0 +1,13 @@
+syntax = "proto3";
+
+package bambulab.v1;
+
+// import "bambulab/common.proto"; once common.proto has a shared message
+// worth embedding (composition, not inheritance — see that file).
+
+// Your command messages go here, e.g.:
+//
+// message InfoCommand {
+//   string sequence_id = 1;
+//   string command = 2;
+// }

proto/bambulab/v2/report.proto

@@ -0,0 +1,9 @@
+syntax = "proto3";
+
+package bambulab.v2;
+
+// import "bambulab/common.proto"; once common.proto has a shared message
+// worth embedding (composition, not inheritance — see that file).
+
+// V2-generation (X1/H2 series) report/response messages go here — e.g.
+// whatever AMS/report-schema fields V2 has that V1 doesn't.

proto/bambulab/v2/request.proto

@@ -0,0 +1,8 @@
+syntax = "proto3";
+
+package bambulab.v2;
+
+// import "bambulab/common.proto"; once common.proto has a shared message
+// worth embedding (composition, not inheritance — see that file).
+
+// V2-generation (X1/H2 series) command messages go here.