feat(linkedin-studio): N17 — baseline-motor (median + variansbånd + minimum-N-refusal) [skip-docs]

Every reading now leads with "vs your own baseline", and no verdict is given
when N is too small to carry one.

- stats.ts: median + medianAbsoluteDeviation (robust pair; mean/stddev stay for
  the alert engine, which wants outlier sensitivity), rollingBaseline with a
  10-post positional window, median ± 1·MAD band floored at 0, and a typed
  insufficient-data refusal below MIN_BASELINE_N=5. readAgainstBaseline returns
  above/within/below-band, or no-verdict when the baseline was refused.
- baselineByGroup + buildBaselineBlock: per-format/per-pillar baselines, each
  judged on its own N; the reported period is excluded from its own baseline and
  compared on its median, not its mean.
- queue-join.ts (new): read-only date join supplying format/pillar from the post
  queue. Every ambiguity resolves to unlabelled, an entry labels at most one
  post, and a missing/broken queue degrades to no labels.
- weekly/monthly reports attach the block unconditionally (refusal included);
  optional in the types, so pre-N17 reports load unchanged.
- CLI: report output leads with the baseline; new `baseline [--by format|pillar]`
  verb with coverage reporting.
- report.md leads with baseline framing and prints the code's reading rather
  than judging the band by eye; WoW loses to the baseline on disagreement.
  analyze.md Step 2a tests whether the drop is real before diagnosing it.

TDD: 58 analytics tests written red first (144 -> 202). test-runner Section 16x,
23 unconditional checks + self-test (247 -> 270; anti-erosion floor 228 -> 251).
tsc clean. All suites green: trends 300, brain 134, editions 72,
specifics-bank 45, contract-gate 33, hooks 191, tests 35, render 60.

Also closes the OKF phase-4 scope follow-up in docs/okf-ingestion/plan.md §8
(coord round 2026-07-25): phase 4 tracks the contract, parse is in scope, and
our claim on read_concept/navigate_bundle is withdrawn as unnecessary.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QxvWAjte7vPcF79QeSRvRJ

scripts/analytics/tests/weekly.test.ts

@@ -9,7 +9,7 @@ import {
   getPostsForWeek,
   generateWeeklyReport,
 } from "../src/reports/weekly.js";
-import { saveBatch, saveWeeklyReport } from "../src/utils/storage.js";
+import { saveBatch, saveWeeklyReport, loadWeeklyReport } from "../src/utils/storage.js";
 import type { PostAnalytics, AnalyticsBatch } from "../src/models/types.js";
 
 // Helper function to create test post data
@@ -662,4 +662,97 @@ describe("weekly", () => {
       assert.match(report.week, /^\d{4}-W\d{2}$/);
     });
   });
+
+  /**
+   * Baseline framing (N17). The report's job is to answer "is this different
+   * from my own normal?" — which requires a baseline built from history BEFORE
+   * the reported week, and an explicit refusal when that history is too thin.
+   */
+  describe("generateWeeklyReport — baseline", () => {
+    // 2026-W03 is Mon 2026-01-12 .. Sun 2026-01-18.
+    function priorPost(day: string, impressions: number): PostAnalytics {
+      return createTestPost({
+        id: `prior-${day}`,
+        publishedDate: day,
+        metrics: { impressions, reactions: 5, comments: 1, shares: 0, clicks: 2, engagementRate: 4 },
+      });
+    }
+
+    test("should attach a baseline built only from earlier weeks", () => {
+      tempDir = setupTempDir();
+      const posts = [
+        priorPost("2025-12-15", 100),
+        priorPost("2025-12-17", 110),
+        priorPost("2025-12-29", 120),
+        priorPost("2025-12-31", 130),
+        priorPost("2026-01-05", 140),
+        // In-week post, deliberately extreme: if it leaked into the baseline the
+        // median would move and the week would be compared against itself.
+        createTestPost({
+          id: "in-week",
+          publishedDate: "2026-01-14",
+          metrics: { impressions: 99999, reactions: 5, comments: 1, shares: 0, clicks: 2, engagementRate: 4 },
+        }),
+      ];
+      saveBatch(tempDir, createTestBatch({ posts }));
+
+      const report = generateWeeklyReport(tempDir, "2026-W03");
+
+      assert.ok(report.baseline, "A generated report must carry a baseline block");
+      assert.equal(report.baseline!.historyBefore, "2026-W03");
+      assert.equal(report.baseline!.impressions.status, "ok");
+      if (report.baseline!.impressions.status !== "ok") return;
+      assert.equal(report.baseline!.impressions.n, 5, "Only the five earlier posts feed it");
+      assert.equal(report.baseline!.impressions.median, 120, "The in-week outlier must not leak in");
+    });
+
+    test("should refuse a baseline verdict when prior history is too thin", () => {
+      tempDir = setupTempDir();
+      const posts = [
+        priorPost("2025-12-15", 100),
+        priorPost("2025-12-17", 110),
+        createTestPost({ id: "in-week", publishedDate: "2026-01-14" }),
+      ];
+      saveBatch(tempDir, createTestBatch({ posts }));
+
+      const report = generateWeeklyReport(tempDir, "2026-W03");
+
+      assert.ok(report.baseline);
+      assert.equal(report.baseline!.impressions.status, "insufficient-data");
+      if (report.baseline!.impressions.status !== "insufficient-data") return;
+      assert.equal(report.baseline!.impressions.n, 2);
+      assert.equal(report.baseline!.impressions.required, 5);
+    });
+
+    test("should refuse rather than omit the block when there is no history at all", () => {
+      tempDir = setupTempDir();
+      saveBatch(tempDir, createTestBatch({
+        posts: [createTestPost({ id: "in-week", publishedDate: "2026-01-14" })],
+      }));
+
+      const report = generateWeeklyReport(tempDir, "2026-W03");
+
+      assert.ok(report.baseline, "An absent block is indistinguishable from a pre-N17 report");
+      assert.equal(report.baseline!.impressions.status, "insufficient-data");
+    });
+
+    test("should carry the baseline through to the saved report on disk", () => {
+      tempDir = setupTempDir();
+      const posts = [
+        priorPost("2025-12-15", 100),
+        priorPost("2025-12-17", 110),
+        priorPost("2025-12-29", 120),
+        priorPost("2025-12-31", 130),
+        priorPost("2026-01-05", 140),
+        createTestPost({ id: "in-week", publishedDate: "2026-01-14" }),
+      ];
+      saveBatch(tempDir, createTestBatch({ posts }));
+
+      generateWeeklyReport(tempDir, "2026-W03");
+      const reloaded = loadWeeklyReport(tempDir, "2026-W03");
+
+      assert.ok(reloaded?.baseline, "The block must survive the round-trip to disk");
+      assert.equal(reloaded!.baseline!.impressions.status, "ok");
+    });
+  });
 });