Fix BUG-001 and BUG-002; add post-submission QA test plan and QA entry

BUG-001: cache-on-save plugin clears page cache on onFormProcessed so
new entries appear in the tracker feed immediately after submission.

BUG-002: disabled Twig template cache (twig.cache: false) so theme
file changes take effect without a manual cache flush.

Also adds bugs-and-fixes.md, corrects TC-P test URLs (.entry suffix),
fixes TC-P.1 expectation (inline login form, not a redirect), and
creates the QA test entry for automated scenario verification.

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

pages/01.tracker/2026-06-18.entry/entry.md

@@ -0,0 +1,15 @@
+---
+title: 'QA Test Entry'
+date: '2026-06-18 10:00'
+template: entry
+published: true
+hero_image: ''
+lat: '35.689487'
+lng: '139.691711'
+location_city: 'Tokyo'
+location_country: 'Japan'
+weather_temp_c: ''
+weather_desc: ''
+---
+
+This is the QA test body. Second sentence for length.