Update Atlassian Rovo and Notion icons (#362)

Updates the Atlassian Rovo and Notion light and dark plugin logos.

## Current state

The two plugins do not expose the supplied light and dark logo artwork
through their plugin manifests.

## Changes

- add light and dark top-level logo assets for Atlassian Rovo
- update the Notion top-level light logo and add its dark logo
- map `logo` and `logoDark` in both plugin manifests
- bump both plugin patch versions

Composer icons, `agents/openai.yaml`, and skill files are unchanged.

## Risk

Low. The change is limited to top-level plugin logo assets and manifest
mappings. The main risk is incorrect appearance on light or dark
surfaces.

## Testing

- focused manifest and logo validation passed for both plugins
- destination assets match the supplied sources by SHA-256
- composer icon paths and bytes match `main`
- `agents/openai.yaml` and skill trees match `main`
- `git diff --check origin/main...HEAD`

The complete plugin validator continues to report pre-existing Rovo
composer-size/TODO checks and pre-existing Notion Markdown-formatting
checks.

## Manual testing

Open both plugins on light and dark surfaces and confirm the
corresponding logo is selected without affecting composer or agent
icons.

## Spiciness

1/5

plugins/atlassian-rovo/.codex-plugin/plugin.json

@@ -1,6 +1,6 @@
 {
   "name": "atlassian-rovo",
-  "version": "1.0.2",
+  "version": "1.0.3",
   "description": "Manage Jira and Confluence fast",
   "author": {
     "name": "Atlassian",
@@ -33,6 +33,7 @@
     "screenshots": [],
     "brandColor": "#0052CC",
     "composerIcon": "./assets/app-icon.png",
-    "logo": "./assets/app-icon.png"
+    "logo": "./assets/logo.png",
+    "logoDark": "./assets/logo-dark.png"
   }
 }

plugins/notion/.codex-plugin/plugin.json

@@ -1,6 +1,6 @@
 {
   "name": "notion",
-  "version": "0.1.4",
+  "version": "0.1.5",
   "description": "Notion workflows for implementation planning, research synthesis, meeting preparation, and knowledge capture.",
   "author": {
     "name": "OpenAI",
@@ -39,6 +39,7 @@
     "brandColor": "#111111",
     "composerIcon": "./assets/notion-small.svg",
     "logo": "./assets/notion.png",
+    "logoDark": "./assets/notion-dark.png",
     "screenshots": []
   }
 }