feat(parse): flexible time parsing for @ suffix

Problem: the @HH:MM time suffix required zero-padded 24-hour format,
forcing users to write due:tomorrow@14:00 instead of due:tomorrow@2pm.

Solution: add normalize_time() that accepts bare hours (9, 14),
H:MM (9:30), am/pm (2pm, 9:30am, 12am), and existing HH:MM format,
normalizing all to canonical HH:MM on save.

spec/parse_spec.lua

@@ -323,6 +323,75 @@ describe('parse', function()
     end)
   end)
 
+  describe('resolve_date with time suffix', function()
+    local today = os.date('*t') --[[@as osdate]]
+    local tomorrow_str = os.date(
+      '%Y-%m-%d',
+      os.time({ year = today.year, month = today.month, day = today.day + 1 })
+    ) --[[@as string]]
+
+    it('resolves bare hour to T09:00', function()
+      local result = parse.resolve_date('tomorrow@9')
+      assert.are.equal(tomorrow_str .. 'T09:00', result)
+    end)
+
+    it('resolves bare military hour to T14:00', function()
+      local result = parse.resolve_date('tomorrow@14')
+      assert.are.equal(tomorrow_str .. 'T14:00', result)
+    end)
+
+    it('resolves H:MM to T09:30', function()
+      local result = parse.resolve_date('tomorrow@9:30')
+      assert.are.equal(tomorrow_str .. 'T09:30', result)
+    end)
+
+    it('resolves HH:MM (existing format) to T09:30', function()
+      local result = parse.resolve_date('tomorrow@09:30')
+      assert.are.equal(tomorrow_str .. 'T09:30', result)
+    end)
+
+    it('resolves 2pm to T14:00', function()
+      local result = parse.resolve_date('tomorrow@2pm')
+      assert.are.equal(tomorrow_str .. 'T14:00', result)
+    end)
+
+    it('resolves 9am to T09:00', function()
+      local result = parse.resolve_date('tomorrow@9am')
+      assert.are.equal(tomorrow_str .. 'T09:00', result)
+    end)
+
+    it('resolves 9:30pm to T21:30', function()
+      local result = parse.resolve_date('tomorrow@9:30pm')
+      assert.are.equal(tomorrow_str .. 'T21:30', result)
+    end)
+
+    it('resolves 12am to T00:00', function()
+      local result = parse.resolve_date('tomorrow@12am')
+      assert.are.equal(tomorrow_str .. 'T00:00', result)
+    end)
+
+    it('resolves 12pm to T12:00', function()
+      local result = parse.resolve_date('tomorrow@12pm')
+      assert.are.equal(tomorrow_str .. 'T12:00', result)
+    end)
+
+    it('rejects hour 24', function()
+      assert.is_nil(parse.resolve_date('tomorrow@24'))
+    end)
+
+    it('rejects 13am', function()
+      assert.is_nil(parse.resolve_date('tomorrow@13am'))
+    end)
+
+    it('rejects minute 60', function()
+      assert.is_nil(parse.resolve_date('tomorrow@9:60'))
+    end)
+
+    it('rejects alphabetic garbage', function()
+      assert.is_nil(parse.resolve_date('tomorrow@abc'))
+    end)
+  end)
+
   describe('command_add', function()
     it('parses simple text', function()
       local desc, meta = parse.command_add('Buy milk')