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+# Configurable Summary Length — Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Add a `summary_length` setting (1=court, 2=moyen, 3=detaille) that controls how detailed article summaries are and how much article body is sent to the LLM.
+
+**Architecture:** New integer setting (1-3) following the existing settings pattern. Affects the classify prompt instruction and body snippet size in the pipeline. Frontend slider with 3 positions.
+
+**Tech Stack:** Rust (sqlx), SolidJS, PostgreSQL
+
+**Spec:** `docs/superpowers/specs/2026-03-26-summary-length-design.md`
+
+---
+
+### Task 1: Migration + backend setting
+
+**Files:**
+- Create: `backend/migrations/20260326000023_add_summary_length.sql`
+- Modify: `backend/src/models/settings.rs`
+- Modify: `backend/src/db/settings.rs`
+- Modify: `backend/src/services/prompts.rs` (test fixture)
+- Modify: `backend/tests/api_syntheses_test.rs` (test fixture)
+- Modify: `backend/tests/pipeline_test.rs` (test fixture)
+- Modify: `CLAUDE.md`
+
+Follow the exact same pattern as `batch_size` was added. This is mechanical.
+
+- [ ] **Step 1: Create migration**
+
+```sql
+ALTER TABLE settings ADD COLUMN summary_length INTEGER NOT NULL DEFAULT 3;
+```
+
+- [ ] **Step 2: Add `summary_length: i32` to all Rust settings structs**
+
+In `backend/src/models/settings.rs`:
+- Add `pub summary_length: i32` to `UserSettings` and `UpdateSettingsRequest` (after `batch_size`)
+- Add to `Default for UserSettings`: `summary_length: 3,`
+- Add to `valid_request()` test fixture: `summary_length: 3,`
+- Add validation:
+```rust
+if !(1..=3).contains(&self.summary_length) {
+    return Err("summary_length must be between 1 and 3".into());
+}
+```
+
+- [ ] **Step 3: Update DB queries in `db/settings.rs`**
+
+Add `summary_length` to `SettingsRow`, `TryFrom` impl, both SQL queries (INSERT columns, VALUES, ON CONFLICT SET, RETURNING), and `.bind()` calls.
+
+- [ ] **Step 4: Update test fixtures**
+
+Add `summary_length: 3,` to:
+- `backend/src/services/prompts.rs` → `test_settings()`
+- `backend/tests/api_syntheses_test.rs` → settings JSON payload
+- `backend/tests/pipeline_test.rs` → `setup_user_with_settings` JSON payload
+
+- [ ] **Step 5: Update CLAUDE.md**
+
+Change `## Database (22 migrations)` to `## Database (23 migrations)`.
+
+- [ ] **Step 6: Build and test**
+
+Run: `cd backend && cargo build && cargo test --lib`
+Expected: All pass
+
+- [ ] **Step 7: Commit**
+
+```bash
+git add backend/migrations/20260326000023_add_summary_length.sql \
+  backend/src/models/settings.rs backend/src/db/settings.rs \
+  backend/src/services/prompts.rs backend/tests/api_syntheses_test.rs \
+  backend/tests/pipeline_test.rs CLAUDE.md
+git commit -m "feat: add summary_length setting (1=court, 2=moyen, 3=detaille)"
+```
+
+---
+
+### Task 2: Prompt and pipeline changes
+
+**Files:**
+- Modify: `backend/src/services/prompts.rs`
+- Modify: `backend/src/services/synthesis.rs`
+
+- [ ] **Step 1: Update `build_article_classify_prompt` to accept `summary_length`**
+
+In `backend/src/services/prompts.rs`, add `summary_length: i32` as a new parameter:
+
+```rust
+pub fn build_article_classify_prompt(
+    title: &str,
+    body_snippet: &str,
+    categories: &[String],
+    summary_length: i32,
+) -> (String, String) {
+```
+
+Change the instruction line from:
+```
+"Genere un titre clair et un resume de 4 a 5 lignes."
+```
+To:
+```rust
+let summary_instruction = match summary_length {
+    1 => "Genere un titre clair et un resume de 3 a 4 lignes.",
+    2 => "Genere un titre clair et un resume de 6 a 8 lignes.",
+    _ => "Genere un titre clair et un resume detaille de 12 a 15 lignes.",
+};
+```
+
+Use `summary_instruction` in the format string instead of the hardcoded line.
+
+- [ ] **Step 2: Update all call sites in `synthesis.rs`**
+
+Find all calls to `build_article_classify_prompt` in `synthesis.rs`. There are 2 (Phase 1 and Phase 2 Brave classify loops). Add `settings.summary_length` as the new argument.
+
+Also update the body snippet size from hardcoded 500 to dynamic:
+
+```rust
+let snippet_size = match settings.summary_length {
+    1 => 500,
+    2 => 2000,
+    _ => 4000,
+};
+let body_snippet: String = body_text.chars().take(snippet_size).collect();
+```
+
+Apply this in both Phase 1 (~line 487) and Phase 2 Brave (~line 665) classify loops.
+
+- [ ] **Step 3: Update prompt tests**
+
+In `prompts.rs` tests, update existing `article_classify_prompt_*` tests to pass `summary_length: 3`. Add a new test:
+
+```rust
+#[test]
+fn article_classify_prompt_short_summary() {
+    let (_, user) = build_article_classify_prompt(
+        "Title", "Content", &["AI".into()], 1,
+    );
+    assert!(user.contains("3 a 4 lignes"));
+}
+
+#[test]
+fn article_classify_prompt_detailed_summary() {
+    let (_, user) = build_article_classify_prompt(
+        "Title", "Content", &["AI".into()], 3,
+    );
+    assert!(user.contains("12 a 15 lignes"));
+}
+```
+
+- [ ] **Step 4: Build and test**
+
+Run: `cd backend && cargo build && cargo test --lib`
+Expected: All pass
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add backend/src/services/prompts.rs backend/src/services/synthesis.rs
+git commit -m "feat: dynamic summary length and body snippet size based on setting"
+```
+
+---
+
+### Task 3: Frontend slider + i18n + types
+
+**Files:**
+- Modify: `frontend/src/types.ts`
+- Modify: `frontend/src/i18n/fr.ts`
+- Modify: `frontend/src/pages/Settings.tsx`
+- Modify: `e2e/tests/generation-live.spec.ts`
+
+- [ ] **Step 1: Update frontend types**
+
+In `frontend/src/types.ts`:
+- Add `summary_length: number;` to `UserSettings` (after `batch_size`)
+- Add `summary_length: 3,` to `DEFAULT_SETTINGS`
+
+- [ ] **Step 2: Add i18n labels**
+
+In `frontend/src/i18n/fr.ts`, add:
+
+```typescript
+'settings.summaryLength': 'Niveau de detail des resumes',
+'settings.summaryLengthHelp': 'Controle la longueur des resumes generes pour chaque article.',
+'settings.summaryShort': 'Court',
+'settings.summaryMedium': 'Moyen',
+'settings.summaryDetailed': 'Detaille',
+```
+
+- [ ] **Step 3: Add slider to Settings.tsx**
+
+In `frontend/src/pages/Settings.tsx`, add a slider in the main settings section (near `max_items_per_category`). Use an `<input type="range">` with min=1, max=3, step=1:
+
+```tsx
+<div>
+  <label for="summaryLength" class="block text-sm font-medium text-gray-700">
+    {t('settings.summaryLength')}
+  </label>
+  <p class="text-xs text-gray-500 mb-2">{t('settings.summaryLengthHelp')}</p>
+  <div class="flex items-center gap-4">
+    <span class="text-xs text-gray-500">{t('settings.summaryShort')}</span>
+    <input
+      type="range"
+      id="summaryLength"
+      min="1"
+      max="3"
+      step="1"
+      class="flex-1 h-2 bg-gray-200 rounded-lg appearance-none cursor-pointer accent-indigo-600"
+      value={settings().summary_length}
+      onInput={(e) =>
+        setSettings((prev) => ({
+          ...prev,
+          summary_length: parseInt(e.currentTarget.value) || 3,
+        }))
+      }
+    />
+    <span class="text-xs text-gray-500">{t('settings.summaryDetailed')}</span>
+  </div>
+  <div class="text-center text-xs text-gray-500 mt-1">
+    {settings().summary_length === 1
+      ? t('settings.summaryShort')
+      : settings().summary_length === 2
+        ? t('settings.summaryMedium')
+        : t('settings.summaryDetailed')}
+  </div>
+</div>
+```
+
+- [ ] **Step 4: Update E2E test fixture**
+
+In `e2e/tests/generation-live.spec.ts`, add `summary_length: 3,` to the settings payload.
+
+- [ ] **Step 5: TypeScript check**
+
+Run: `cd frontend && npx tsc --noEmit`
+Expected: No errors
+
+- [ ] **Step 6: Commit**
+
+```bash
+git add frontend/src/types.ts frontend/src/i18n/fr.ts \
+  frontend/src/pages/Settings.tsx e2e/tests/generation-live.spec.ts
+git commit -m "feat: add summary length slider to Settings page"
+```