Curation v2 step 2: Claude Opus 5 editor, the Brief, per-provider budgets

- AnthropicBackend (Messages API, cached system block, output_config.effort,
  server-side fallbacks, refusal surfaced as an error); Llms { bulk, editor }
  with editor_or_bulk(); PriceTable-based UsageMeter per provider.
- [anthropic], [editorial], deepseek.max_concurrent_requests and
  curation.max_article_count config; startup logs resolved providers.
- Budget day is the UTC date of started_at, preloaded from
  runs.provider_costs_json; finish_run writes provider_costs_json and
  config_json. Stage A batches run concurrently with per-batch budget checks.
- Editor prompt with one-line "why" per pick; no minimum lineup size;
  --max-articles is a ceiling; top-up branch deleted; why stored on picks and
  issue_articles.why and rendered in chapters and In this issue.
- Summaries on the editor client (3k-token input, concurrency 4, bulk then
  excerpt fallback); "The Brief" replaces From the Editor; section intros gone.
- Colophon carries per-provider costs and models.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01A1rCLQeKBgnBo3oTgHuTMe

tests/m3_curation.rs

@@ -17,7 +17,7 @@ use std::collections::BTreeSet;
 use std::path::{Path, PathBuf};
 use std::process::Command;
 
-use daily_epub::curate::editorial::FrontPageResponse;
+use daily_epub::curate::editorial::BriefResponse;
 use daily_epub::curate::profile;
 use daily_epub::curate::score::parse_score_response;
 use daily_epub::curate::select::parse_selection_response;
@@ -130,35 +130,41 @@ fn stage_b_fixture_parses_into_a_lineup() {
     );
 }
 
-/// Stage C's front-page response must deserialize into a 250–400 word editor's
-/// note plus per-section intros (§3.6).
+/// The Brief must deserialize into 120–200 words of plain prose that names at
+/// least three picks by title (§14.2). Section intros are gone.
 #[test]
-fn stage_c_fixture_parses_into_a_front_page() {
-    let response: FrontPageResponse = serde_json::from_str(&fixture("deepseek_front_page.json"))
-        .expect("the front-page fixture must match FrontPageResponse");
+fn stage_c_fixture_parses_into_the_brief() {
+    let response: BriefResponse = serde_json::from_str(&fixture("claude_brief.json"))
+        .expect("the brief fixture must match BriefResponse");
 
-    let words = response.from_the_editor.split_whitespace().count();
+    let words = response.brief.split_whitespace().count();
     assert!(
-        (150..=450).contains(&words),
-        "From the Editor is {words} words; the prompt asks for 250-400"
+        (100..=220).contains(&words),
+        "The Brief is {words} words; the prompt asks for 120-200"
     );
     assert!(
-        response.from_the_editor.contains("\n\n"),
-        "the prompt asks for 2-4 blank-line separated paragraphs"
+        !response.brief.contains("- ") && !response.brief.contains('#'),
+        "no bullets or headings in the brief"
     );
+    let titles = response.brief.matches('"').count() / 2;
     assert!(
-        !response.from_the_editor.contains("- "),
-        "no bullet lists on the front page"
+        titles >= 3,
+        "the brief names at least three picks; found {titles}"
     );
-
-    assert!(response.section_intros.len() >= 2);
-    for (section, intro) in &response.section_intros {
-        let words = intro.split_whitespace().count();
+    for banned in [
+        "delve",
+        "dive",
+        "explore",
+        "a mix of",
+        "something for everyone",
+    ] {
         assert!(
-            (10..=90).contains(&words),
-            "intro for {section} is {words} words; the prompt asks for 35-60"
+            !response.brief.to_lowercase().contains(banned),
+            "banned phrase {banned}"
         );
     }
+    let value: serde_json::Value = serde_json::from_str(&fixture("claude_brief.json")).unwrap();
+    assert!(value.get("section_intros").is_none());
 }
 
 /// The taste profile is seeded from this file; a broken export would silently