Add PM extension (Projects, Work Logs, Comments) + Quill rich-text UI

Projects: Brick-backed model with list/detail screens and nav entry.
Work Logs: per-contributor time ledger, assignee running-clock +
helper logged minutes with Hours/Minutes input; pause-after-save and
helper-deduct prompts.
Comments: threaded comments with file attachments and Quill composer.
Detail screen: tabbed layout (Work Log / Comments / Activity),
editable title + description via edit dialog, Quill-rendered
descriptions with legacy plain-text fallback.
Create dialog: fixed-width (480px max), Quill description editor.
Shared QuillFieldEditor + QuillReadOnly widgets extracted for reuse.
RLS: hardened activity-log actor binding, immutable creator_id/
created_at triggers, SECURITY INVOKER visibility helper,
append-only work-log and scoped comment policies.
Brick migration for project_id FK on programmer_tasks.

Co-Authored-By: claude-flow <ruv@ruv.net>

lib/utils/task_duration.dart

@@ -29,14 +29,17 @@ DateTime? resolveExecutionStart(
 }
 
 /// Computes the effective worked duration, subtracting all paused intervals
-/// between the resolved start and [endAt].
+/// between the resolved start and [endAt], then subtracting [adjustment]
+/// (e.g. time reassigned to another task when the user helped elsewhere).
 ///
 /// [events] must be in DESCENDING order (newest first) — the same order
-/// returned by activity-log queries with `ascending: false`.
+/// returned by activity-log queries with `ascending: false`. The result never
+/// goes below zero.
 Duration computeEffectiveDuration({
   required DateTime? fallbackStartedAt,
   required DateTime endAt,
   required List<DurationEvent> events,
+  Duration adjustment = Duration.zero,
 }) {
   final start = resolveExecutionStart(events, fallbackStartedAt);
   if (start == null || !endAt.isAfter(start)) return Duration.zero;
@@ -67,7 +70,7 @@ Duration computeEffectiveDuration({
     pausedTotal += endAt.difference(pausedSince);
   }
 
-  final total = endAt.difference(start) - pausedTotal;
+  final total = endAt.difference(start) - pausedTotal - adjustment;
   return total.isNegative ? Duration.zero : total;
 }