fix(audit): require integer phase0 summary row limits

Require non-negative integer maxSessions/maxChannels/maxSkipReasons in summary core and both phase0 summary/capture CLIs to prevent silent flooring of fractional values. Architecture/protocol diagrams reviewed; no flow or API shape changes required.

src/audit/phase0BaselineSummary.test.ts

@@ -222,6 +222,14 @@ describe('summarizePhase0Baseline', () => {
     expect(() => summarizePhase0Baseline(events, { maxChannels: -1 })).toThrow('maxChannels');
     expect(() => summarizePhase0Baseline(events, { maxSkipReasons: -1 })).toThrow('maxSkipReasons');
   });
+
+  it('rejects non-integer max limits', () => {
+    const events: AuditEvent[] = [];
+
+    expect(() => summarizePhase0Baseline(events, { maxSessions: 1.5 })).toThrow('maxSessions');
+    expect(() => summarizePhase0Baseline(events, { maxChannels: 1.5 })).toThrow('maxChannels');
+    expect(() => summarizePhase0Baseline(events, { maxSkipReasons: 1.5 })).toThrow('maxSkipReasons');
+  });
 });
 
 describe('renderPhase0BaselineMarkdown', () => {

src/audit/phase0BaselineSummary.ts

@@ -126,10 +126,13 @@ function normalizeLimit(value: number | undefined, optionName: string): number |
   if (!Number.isFinite(value)) {
     throw new Error(`${optionName} must be a finite number.`);
   }
+  if (!Number.isInteger(value)) {
+    throw new Error(`${optionName} must be an integer greater than or equal to 0.`);
+  }
   if (value < 0) {
     throw new Error(`${optionName} must be greater than or equal to 0.`);
   }
-  return Math.floor(value);
+  return value;
 }
 
 function percentile(sortedAscending: number[], pct: number): number {
@@ -197,7 +200,7 @@ function sortGroups(groups: Map<string, RunCounter>, limit?: number): RunOutcome
     });
 
   if (typeof limit === 'number' && Number.isFinite(limit)) {
-    return rows.slice(0, Math.floor(limit));
+    return rows.slice(0, limit);
   }
   return rows;
 }
@@ -213,7 +216,7 @@ function sortSkipReasons(reasons: Map<string, number>, limit?: number): Reaction
     }));
 
   if (typeof limit === 'number' && Number.isFinite(limit)) {
-    return rows.slice(0, Math.floor(limit));
+    return rows.slice(0, limit);
   }
   return rows;
 }