Add routines module and full goal management

Routines: workout, meditation and must-do routines with timed, rep and
tick steps, sets and rest. A library screen, a builder with templates
and drag-to-reorder steps, and a full-screen player that auto-advances
timed phases, counts backgrounding and logs broken chains as partial.

Goals: a goal editor (deadline, colour, category, default class, archive),
routines linked to goals, and a goal field on tasks and routines. Tasks
added from inside a goal are now actually attached to it via parentId.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KhQh614DMeYoQEH9SoMRUw

frontend/lib/Grounded/about/internal/application/RoutinePhase.dart

@@ -0,0 +1,40 @@
+import '../../external/data/RoutineStep.dart';
+import 'StepMode.dart';
+
+/// One beat of a running routine — a single work set or the rest after it.
+/// The runner walks a flat list of these, so "set 2 of 4" and "rest" are the
+/// same kind of thing to the clock.
+class RoutinePhase {
+  /// Index of the step this phase belongs to.
+  final int stepIndex;
+
+  final RoutineStep step;
+
+  /// 1-based set number within the step.
+  final int set;
+
+  final bool rest;
+
+  RoutinePhase({
+    required this.stepIndex,
+    required this.step,
+    this.set = 1,
+    this.rest = false,
+  });
+
+  /// Seconds the clock runs for. Zero means the phase waits for a tap.
+  int get seconds {
+    if (rest) {
+      return step.restSeconds;
+    }
+    return step.mode == StepMode.Timed ? step.timerSeconds : 0;
+  }
+
+  bool get countsDown {
+    return seconds > 0;
+  }
+
+  bool get lastSet {
+    return set >= step.sets;
+  }
+}