feat(skills): add image vision skill for WhatsApp (#770)

* chore: prepare image-vision skill for template regeneration

- Delete stale modify/*.ts templates (built against 1.1.2)
- Update core_version to 1.2.6
- Strip fork-specific details from intent docs

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

* feat(skills): regenerate image-vision modify/ templates against upstream

Templates regenerated against upstream 1.2.6:
- src/container-runner.ts: imageAttachments field in ContainerInput
- src/index.ts: parseImageReferences + threading to runAgent
- src/channels/whatsapp.ts: downloadMediaMessage + image handling block
- src/channels/whatsapp.test.ts: image mocks + 4 test cases
- container/agent-runner/src/index.ts: ContentBlock types, pushMultimodal, image loading

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

* test: update image-vision tests for upstream templates

- Relax downloadMediaMessage import pattern check (multi-line import)
- Remove check for [Image - processing failed] (not in upstream template)
- Add vitest.skills.config.ts for skill package test runs

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

* chore: update image-vision core_version to 1.2.8

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

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

.claude/skills/add-image-vision/manifest.yaml

@@ -0,0 +1,20 @@
+skill: add-image-vision
+version: 1.1.0
+description: "Add image vision to NanoClaw agents via WhatsApp image attachments"
+core_version: 1.2.8
+adds:
+  - src/image.ts
+  - src/image.test.ts
+modifies:
+  - src/channels/whatsapp.ts
+  - src/channels/whatsapp.test.ts
+  - src/container-runner.ts
+  - src/index.ts
+  - container/agent-runner/src/index.ts
+structured:
+  npm_dependencies:
+    sharp: "^0.34.5"
+  env_additions: []
+conflicts: []
+depends: []
+test: "npx vitest run --config vitest.skills.config.ts .claude/skills/add-image-vision/tests/image-vision.test.ts"