chore(release): bump v1.18.2 [skip-docs]

Version 1.18.2 in plugin.json, the README badge and SECURITY.md, with the changelog entry: screenshots regenerated from the current demo, older sets removed, manifest gate added. Not tagged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -7,6 +7,19 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [1.18.2] - 2026-09-23
+
+### Changed
+- Regenerated the playground screenshots from the current demo: 24 PNGs (12 surfaces × 2 themes) in `playground/screenshots/v1.15.0/`, including the dark onboarding view removed in 1.18.1. The README gallery, `docs/playground.md` and `tests/screenshot/README.md` describe this set.
+- `tests/screenshot/run.mjs` clears PNGs a previous run left behind and writes `playground/screenshots/MANIFEST.json` (sha256 per PNG and of the demo state rendered).
+- Aligned the demo project description with its reports (a housing-allowance chatbot, not building permits) and set six demo fixtures equal to the corrected AI Act deadlines already shown in the demo; `tests/kb-update/test-demo-project-description.test.mjs` keeps the demo block equal to its fixtures.
+
+### Removed
+- The v1.10.0, v1.11.0, v1.14.0 and v2-mockup screenshot sets (77 PNGs), which showed an earlier demo, and `tests/screenshot/shoot-mockup.local.mjs`, whose input file is not in the repository.
+
+### Added
+- `tests/kb-update/test-screenshots-manifest.test.mjs`: fails when a PNG in the tree is not output of the latest screenshot run, a PNG changed, the demo state changed after the run, or a doc points at another screenshot directory.
+
 ## [1.18.1] - 2026-09-23
 
 ### Changed