feat(embed,config): add multilingual-e5-large + flip default config (fb-39b)

Task 1: Add multilingual-e5-large arm to kebab-embed-local::resolve_model with tests for 1024-dim variants and error cases.

Task 2: Flip kebab-config defaults from e5-small (384-dim) to e5-large (1024-dim) across defaults(), test assertions, and TOML template.

All tests pass; clippy clean.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/kebab-config/src/lib.rs

@@ -302,9 +302,9 @@ impl Config {
             models: ModelsCfg {
                 embedding: EmbeddingModelCfg {
                     provider: "fastembed".to_string(),
-                    model: "multilingual-e5-small".to_string(),
+                    model: "multilingual-e5-large".to_string(),
                     version: "v1".to_string(),
-                    dimensions: 384,
+                    dimensions: 1024,
                     batch_size: 64,
                 },
                 llm: LlmCfg {
@@ -764,7 +764,8 @@ mod tests {
         let c = Config::defaults();
         assert_eq!(c.rag.score_gate, 0.30);
         assert_eq!(c.chunking.target_tokens, 500);
-        assert_eq!(c.models.embedding.dimensions, 384);
+        assert_eq!(c.models.embedding.model, "multilingual-e5-large");
+        assert_eq!(c.models.embedding.dimensions, 1024);
         assert_eq!(c.search.rrf_k, 60);
     }
 
@@ -947,9 +948,9 @@ chunker_version = "md-heading-v1"
 
 [models.embedding]
 provider = "fastembed"
-model = "multilingual-e5-small"
+model = "multilingual-e5-large"
 version = "v1"
-dimensions = 384
+dimensions = 1024
 batch_size = 64
 
 [models.llm]

crates/kebab-embed-local/src/lib.rs

@@ -193,17 +193,18 @@ fn prefix_input(input: &EmbeddingInput<'_>) -> String {
 }
 
 /// Resolve a `config.models.embedding.model` string to a fastembed
-/// `EmbeddingModel` enum variant. Only `multilingual-e5-small` is wired
-/// for p3-2; additional model names should be added (and their dims
-/// pinned in tests) as needed.
+/// `EmbeddingModel` enum variant. Currently supports `multilingual-e5-small`
+/// (384-dim) and `multilingual-e5-large` (1024-dim); additional model names
+/// should be added (and their dims pinned in tests) as needed.
 fn resolve_model(name: &str) -> Result<EmbeddingModel> {
     match name {
         "multilingual-e5-small" => Ok(EmbeddingModel::MultilingualE5Small),
+        "multilingual-e5-large" => Ok(EmbeddingModel::MultilingualE5Large),
         other => anyhow::bail!(
             "kb-embed-local: unsupported embedding model {other:?}; \
-             this adapter currently only ships `multilingual-e5-small`. \
-             Add a new arm to `resolve_model` (and a fastembed feature \
-             flag if needed) to support more."
+             this adapter currently ships `multilingual-e5-small` and \
+             `multilingual-e5-large`. Add a new arm to `resolve_model` \
+             (and a fastembed feature flag if needed) to support more."
         ),
     }
 }
@@ -294,6 +295,12 @@ mod tests {
         resolve_model("multilingual-e5-small").expect("default model resolves");
     }
 
+    #[test]
+    fn resolve_model_supports_e5_large() {
+        let m = resolve_model("multilingual-e5-large").expect("e5-large should resolve");
+        let _ = m;
+    }
+
     #[test]
     fn resolve_unknown_model_errors() {
         let err = resolve_model("not-a-real-model").expect_err("unknown model errors");
@@ -301,6 +308,21 @@ mod tests {
         assert!(msg.contains("unsupported embedding model"), "msg={msg}");
     }
 
+    // ── check_dim ────────────────────────────────────────────────────
+
+    #[test]
+    fn check_dim_passes_for_1024() {
+        check_dim(1024, 1024).expect("matching dims must pass");
+    }
+
+    #[test]
+    fn check_dim_rejects_384_vs_1024() {
+        let err = check_dim(384, 1024).expect_err("dim mismatch must error");
+        let msg = format!("{err}");
+        assert!(msg.contains("384") && msg.contains("1024"),
+            "error must mention both dims, got: {msg}");
+    }
+
     // expand_path tests live in `kb-config::paths`. The adapter imports
     // it and trusts the upstream coverage rather than duplicating it.
 }