domain/record, runner: add DurationMS to RunRecord (T2.1, T2.2)

Add DurationMS int64 field to RunRecord and measure wall-clock
start→finish in RunJob; StartOnly jobs record 0.

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

src/domain/record.go

@@ -4,12 +4,13 @@ package domain
 // output is also written to a log file; the in-memory Output copy exists so the
 // latest run can be displayed without reopening the log on every repaint.
 type RunRecord struct {
-	Time    string `yaml:"time"`
-	JobID   int    `yaml:"job_id"`
-	JobName string `yaml:"job_name"`
-	Trigger string `yaml:"trigger,omitempty"`
-	State   string `yaml:"state"`
-	Detail  string `yaml:"detail"`
-	LogFile string `yaml:"log_file,omitempty"`
-	Output  string `yaml:"output,omitempty"`
+	Time       string `yaml:"time"`
+	JobID      int    `yaml:"job_id"`
+	JobName    string `yaml:"job_name"`
+	Trigger    string `yaml:"trigger,omitempty"`
+	State      string `yaml:"state"`
+	Detail     string `yaml:"detail"`
+	LogFile    string `yaml:"log_file,omitempty"`
+	Output     string `yaml:"output,omitempty"`
+	DurationMS int64  `yaml:"duration_ms,omitempty"`
 }