Add parser doctor, offline queue, tag inheritance, logo, MIT license

Parser doctor:
- validateContent() with error/warning severity levels
- Errors: invalid date, invalid priority, reminder without due,
  invalid reminder unit
- Warnings: time without date, past date, multiple metadata,
  typo detection with correction suggestions
- 21 new tests in ParserDoctorTest

Tag inheritance:
- extractTasks() accepts memoTags parameter
- Tasks without #tags inherit memo-level tags

Offline queue:
- PendingSyncEntity + PendingSyncDao for queued edits
- MemoRepository queues failed API calls, drains on next sync
- Sync status banner: "synced N min ago" / "offline · N pending"

UI:
- Parser doctor banner in tasks tab with inline highlighting
- Error/warning dots on task rows
- Pivot headers with absolute positioning and measured widths
- Logo in settings about section (Canvas-drawn circle variant)

Other:
- MIT license
- Logo design spec (LOGO.md)
- Concentric circle logo: pink circle, black+teal 47° annular wedge
- .gitignore updated for dev artifacts

144 tests passing.

Co-Authored-By: Claude Opus 4.6 (1M context)

Signed-off-by: Avinal Kumar <avinal.xlvii@gmail.com>

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Avinal Kumar
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.