feat: Languageインストラクションの追加

crates/pod/src/factory.rs

@@ -643,6 +643,7 @@ permission = "write"
         let ctx = SystemPromptContext {
             now: chrono::Utc::now(),
             cwd: &root,
+            language: manifest::defaults::WORKER_LANGUAGE,
             scope: &scope,
             tool_names: Vec::new(),
             agents_md: None,

crates/pod/src/pod.rs

@@ -879,10 +879,12 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
             };
         let resident_exposure_snapshots =
             self.resident_exposure_snapshots(&resident, &resident_workflows);
+        let worker_language = worker_language(&self.manifest.worker);
         let scope_snapshot = self.scope.snapshot();
         let ctx = SystemPromptContext {
             now: chrono::Utc::now(),
             cwd: &self.pwd,
+            language: worker_language,
             scope: &scope_snapshot,
             tool_names,
             agents_md: agents_md_read.body,
@@ -2342,6 +2344,15 @@ fn memory_language(cfg: &manifest::MemoryConfig) -> &str {
         .unwrap_or(manifest::defaults::MEMORY_LANGUAGE)
 }
 
+fn worker_language(cfg: &manifest::WorkerManifest) -> &str {
+    let language = cfg.language.trim();
+    if language.is_empty() {
+        manifest::defaults::WORKER_LANGUAGE
+    } else {
+        language
+    }
+}
+
 /// Outcome of a single extract iteration. Internal to
 /// `try_post_run_extract` / `run_extract_once`.
 enum ExtractDecision {
@@ -3152,6 +3163,7 @@ mod build_summary_prompt_tests {
     fn worker_manifest_generation_settings_become_request_config() {
         let manifest = WorkerManifest {
             instruction: "unused".into(),
+            language: manifest::defaults::WORKER_LANGUAGE.into(),
             max_tokens: Some(1024),
             max_turns: None,
             temperature: Some(0.2),

crates/pod/src/prompt/system.rs

@@ -144,6 +144,8 @@ impl std::fmt::Debug for SystemPromptTemplate {
 pub struct SystemPromptContext<'a> {
     pub now: DateTime<Utc>,
     pub cwd: &'a Path,
+    /// Language policy exposed to instruction templates as `{{ language }}`.
+    pub language: &'a str,
     pub scope: &'a Scope,
     pub tool_names: Vec<String>,
     /// Project-level instructions read from the nearest `AGENTS.md`.
@@ -181,6 +183,7 @@ impl<'a> SystemPromptContext<'a> {
             Value::from(self.now.to_rfc3339_opts(SecondsFormat::Secs, true)),
         );
         root.insert("cwd".into(), Value::from(self.cwd.display().to_string()));
+        root.insert("language".into(), Value::from(self.language));
         root.insert(
             "tools".into(),
             Value::from(
@@ -328,6 +331,7 @@ mod tests {
         SystemPromptContext {
             now: fixed_now(),
             cwd,
+            language: manifest::defaults::WORKER_LANGUAGE,
             scope,
             tool_names: tools,
             agents_md,
@@ -345,6 +349,7 @@ mod tests {
         SystemPromptContext {
             now: fixed_now(),
             cwd,
+            language: manifest::defaults::WORKER_LANGUAGE,
             scope,
             tool_names: Vec::new(),
             agents_md: None,
@@ -380,6 +385,9 @@ mod tests {
         let rendered = tmpl
             .render(&ctx(dir.path(), &scope, vec!["Read".into()], None))
             .unwrap();
+        // Builtin default body must expose the language policy.
+        assert!(rendered.contains("## Language"));
+        assert!(rendered.contains("`language`: `match the user's language"));
         // Trailing section must be present.
         assert!(rendered.contains("## Working boundaries"));
         assert!(rendered.contains("Readable:"));