feat(21-01): implement triage-note formatter + TriageNoteEvidence contract

- formatTriageNote renders verdict/confidence/summary/reasons/blast-radius
  (both branches)/recommended actions/current remediation state as prose
- Routes indicator URLs through sanitizeUrl and the whole assembled output
  through sanitizeNoteText before returning
- Handles null verdict/confidence gracefully
- Exports TriageNoteEvidence interface for Plan 02
- All 9 formatter tests pass

lib/services/triage-note-format.ts

@@ -0,0 +1,133 @@
+/**
+ * Triage-note formatter (Phase 21, NOTE-01).
+ *
+ * Pure, deterministic function that turns a structured campaign-evidence
+ * object (`TriageNoteEvidence`) into human-readable prose suitable for
+ * posting as an internal Autotask `TicketNotes` entry. No DB, network, or
+ * Autotask dependency — Plan 02's service gathers evidence and calls
+ * `formatTriageNote()`, then writes the resulting text.
+ *
+ * Every URL and the entire assembled string are routed through
+ * `triage-note-sanitize.ts` before being returned, so a secret/token/full
+ * malicious query string embedded in ANY source field (summary, reasons,
+ * URLs) is stripped regardless of which field it came from (D-04 "full
+ * picture" + NOTE-01 sanitization requirement).
+ */
+
+import { sanitizeUrl, sanitizeNoteText } from './triage-note-sanitize';
+import type { BlastRadiusResult } from './mimecast-blast-radius';
+
+export interface TriageNoteEvidence {
+  campaignId: string;
+  reportCount: number;
+  companyName?: string | null;
+  subject?: string | null;
+  verdict: 'SPAM' | 'UNWANTED' | 'THREAT' | null;
+  confidence: number | null;
+  summary: string | null;
+  reasons: string[];
+  recommendedActions: string[];
+  requiresApproval: boolean;
+  blastRadius: BlastRadiusResult;
+  remediationActions: Array<{
+    actionType: string;
+    status: string;
+    approvedBy: string | null;
+    approvedAt: string | null;
+  }>;
+  urls: string[];
+}
+
+function formatBlastRadiusSection(blastRadius: BlastRadiusResult): string {
+  if (blastRadius.status === 'unavailable') {
+    const detail = blastRadius.error ? ` — ${blastRadius.error}` : '';
+    return `Blast Radius: unavailable (reason: ${blastRadius.reason})${detail}`;
+  }
+
+  return [
+    'Blast Radius:',
+    `  Matched: ${blastRadius.matched}`,
+    `  Delivered: ${blastRadius.delivered}`,
+    `  Held: ${blastRadius.held}`,
+    `  Rejected: ${blastRadius.rejected}`,
+    `  Clicked: ${blastRadius.clicked}`,
+  ].join('\n');
+}
+
+function formatRemediationSection(
+  remediationActions: TriageNoteEvidence['remediationActions']
+): string {
+  if (remediationActions.length === 0) {
+    return 'Current Remediation State: No action has been taken yet — recommended actions are proposed-only.';
+  }
+
+  const lines = remediationActions.map((action) => {
+    const approver =
+      action.approvedBy || action.approvedAt
+        ? ` (approver: ${action.approvedBy ?? 'unknown'}, approved at: ${action.approvedAt ?? 'unknown'})`
+        : '';
+    return `  - ${action.actionType} — ${action.status}${approver}`;
+  });
+
+  return ['Current Remediation State:', ...lines].join('\n');
+}
+
+/**
+ * Assemble the full triage note as human-readable prose, sanitized so no
+ * secret/token/full malicious URL query string survives regardless of which
+ * evidence field it originated from.
+ */
+export function formatTriageNote(evidence: TriageNoteEvidence): string {
+  const verdictLabel = evidence.verdict ?? 'not yet classified';
+  const confidenceLabel =
+    evidence.confidence === null || evidence.confidence === undefined
+      ? 'not yet classified'
+      : String(evidence.confidence);
+
+  const headerLine = `Phishing Triage Summary — Campaign ${evidence.campaignId} (${evidence.reportCount} report${evidence.reportCount === 1 ? '' : 's'})`;
+
+  const classificationSection = [
+    'Classification:',
+    `  Verdict: ${verdictLabel}`,
+    `  Confidence: ${confidenceLabel}`,
+    `  Summary: ${evidence.summary ?? 'not yet classified'}`,
+  ].join('\n');
+
+  const reasonsSection =
+    evidence.reasons.length > 0
+      ? ['Reasons:', ...evidence.reasons.map((r) => `  - ${r}`)].join('\n')
+      : 'Reasons: none recorded';
+
+  const blastRadiusSection = formatBlastRadiusSection(evidence.blastRadius);
+
+  const recommendedActionsSection = [
+    'Recommended Actions:',
+    evidence.recommendedActions.length > 0
+      ? evidence.recommendedActions.map((a) => `  - ${a}`).join('\n')
+      : '  - none',
+    evidence.requiresApproval ? '  (requires operator approval)' : '  (no approval required)',
+  ].join('\n');
+
+  const remediationSection = formatRemediationSection(evidence.remediationActions);
+
+  const urlsSection =
+    evidence.urls.length > 0
+      ? ['Indicator URLs:', ...evidence.urls.map((u) => `  - ${sanitizeUrl(u)}`)].join('\n')
+      : null;
+
+  const sections = [
+    headerLine,
+    evidence.companyName ? `Company: ${evidence.companyName}` : null,
+    evidence.subject ? `Subject: ${evidence.subject}` : null,
+    classificationSection,
+    reasonsSection,
+    blastRadiusSection,
+    recommendedActionsSection,
+    remediationSection,
+    urlsSection,
+  ].filter((s): s is string => s !== null);
+
+  const assembled = sections.join('\n\n');
+
+  return sanitizeNoteText(assembled);
+}