docs: enrich module docs with binary analysis cross-references

src/api/models.rs

@@ -1,4 +1,10 @@
 //! Model definitions and lookup.
+//!
+//! Maps our user-friendly model names to internal Antigravity identifiers.
+//! The `model_enum` values are protobuf enum numbers extracted from extension.js:
+//! placeholder models use 1000+N (e.g. M26→1026), while named models like
+//! `MODEL_CLAUDE_4_OPUS` have their own enum values (e.g. 290).
+//! See `docs/ls-binary-analysis.md` for the full enum mapping.
 
 /// Model definition: friendly name → (antigravity_id, protobuf_enum, label).
 pub(crate) struct ModelDef {