fix(#2554): preserve leading zero before decimal in getMilestonePhaseFilter

Replace /^0+/ with /^0+(?=\d)/ so "00.1" normalizes to "0.1" instead of
".1". This fixes the Set membership mismatch between the ROADMAP phase ID
normalizer and the disk-dir extractor (which yields "0.1" for "00.1-slug"),
preventing decimal phase directories from being silently excluded from
progress counts on every state write.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

get-shit-done/bin/lib/core.cjs

@@ -1566,7 +1566,7 @@ function getMilestonePhaseFilter(cwd) {
   }
 
   const normalized = new Set(
-    [...milestonePhaseNums].map(n => (n.replace(/^0+/, '') || '0').toLowerCase())
+    [...milestonePhaseNums].map(n => (n.replace(/^0+(?=\d)/, '') || '0').toLowerCase())
   );
 
   function isDirInMilestone(dirName) {

tests/bug-2554-decimal-phase-filter.test.cjs

@@ -0,0 +1,67 @@
+'use strict';
+
+/**
+ * Bug #2554: getMilestonePhaseFilter over-strips leading zeros on decimal phase IDs.
+ *
+ * "00.1" → ".1" (wrong) vs "0.1" (correct), causing disk-scan to miss
+ * directories like "00.1-app-namespace-rename" and silently under-count phases.
+ *
+ * Fix: replace /^0+/ with /^0+(?=\d)/ so the leading zero before the decimal
+ * point is preserved.
+ */
+
+const { test, describe } = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('node:fs');
+const path = require('node:path');
+const os = require('node:os');
+
+const { getMilestonePhaseFilter } = require('../get-shit-done/bin/lib/core.cjs');
+
+function makeTmpProject(roadmapContent) {
+  const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'gsd-2554-'));
+  const planningDir = path.join(dir, '.planning');
+  fs.mkdirSync(planningDir);
+  fs.writeFileSync(path.join(planningDir, 'ROADMAP.md'), roadmapContent, 'utf-8');
+  return dir;
+}
+
+describe('getMilestonePhaseFilter decimal phase IDs (#2554)', () => {
+  test('includes "00.1-slug" dir when ROADMAP has Phase 00.1', () => {
+    const roadmap = [
+      '## Milestone: Test',
+      '### Phase 00.1: App Namespace Rename',
+      '### Phase 1: Core Setup',
+    ].join('\n');
+    const cwd = makeTmpProject(roadmap);
+    try {
+      const filter = getMilestonePhaseFilter(cwd);
+      assert.ok(filter('00.1-app-namespace-rename'), '"00.1-app-namespace-rename" must be included');
+      assert.ok(filter('1-core-setup'), '"1-core-setup" must be included');
+    } finally {
+      fs.rmSync(cwd, { recursive: true, force: true });
+    }
+  });
+
+  test('does not lose the pre-decimal zero: "00.1" normalizes to "0.1" not ".1"', () => {
+    // The normalization regex applied to the phase ID from ROADMAP
+    const normalize = n => (n.replace(/^0+(?=\d)/, '') || '0').toLowerCase();
+    assert.strictEqual(normalize('00.1'), '0.1');
+    assert.strictEqual(normalize('0'),    '0');
+    assert.strictEqual(normalize('01'),   '1');
+    assert.strictEqual(normalize('10'),   '10');
+    assert.strictEqual(normalize('00.1'), '0.1'); // key regression case
+  });
+
+  test('dir extractor and normalizer agree on "00.1-slug"', () => {
+    const dirName = '00.1-app-namespace-rename';
+    const m = dirName.match(/^0*(\d+[A-Za-z]?(?:\.\d+)*)/);
+    assert.ok(m, 'regex must match');
+    assert.strictEqual(m[1], '0.1');
+
+    const normalize = n => (n.replace(/^0+(?=\d)/, '') || '0').toLowerCase();
+    assert.strictEqual(normalize('00.1'), '0.1');
+
+    assert.strictEqual(m[1], normalize('00.1'), 'extractor and normalizer must agree');
+  });
+});