feat: add defaultModel to plugin manifests

Add defaultModel: sonnet to all plugin manifests that have agents,
establishing the plugin-level default in the model inheritance chain.

Version bumps:
- projman: 3.2.0 → 3.3.0 (minor: new feature)
- pr-review: 1.0.0 → 1.1.0 (minor: new feature)
- data-platform: 1.0.0 → 1.1.0 (minor: new feature)
- viz-platform: 1.0.0 → 1.1.0 (minor: new feature)
- code-sentinel: 1.0.0 → 1.0.1 (patch: config addition)
- contract-validator: 1.0.0 → 1.1.0 (minor: new feature)

Fixes #305

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

plugins/code-sentinel/.claude-plugin/plugin.json

@@ -1,7 +1,8 @@
 {
   "name": "code-sentinel",
   "description": "Security scanning and code refactoring tools",
-  "version": "1.0.0",
+  "version": "1.0.1",
+  "defaultModel": "sonnet",
   "author": {
     "name": "Leo Miranda",
     "email": "leobmiranda@gmail.com"

plugins/contract-validator/.claude-plugin/plugin.json

@@ -1,6 +1,7 @@
 {
   "name": "contract-validator",
-  "version": "1.0.0",
+  "version": "1.1.0",
+  "defaultModel": "sonnet",
   "description": "Cross-plugin compatibility validation and Claude.md agent verification",
   "author": {
     "name": "Leo Miranda",

plugins/data-platform/.claude-plugin/plugin.json

@@ -1,6 +1,7 @@
 {
   "name": "data-platform",
-  "version": "1.0.0",
+  "version": "1.1.0",
+  "defaultModel": "sonnet",
   "description": "Data engineering tools with pandas, PostgreSQL/PostGIS, and dbt integration",
   "author": {
     "name": "Leo Miranda",

plugins/pr-review/.claude-plugin/plugin.json

@@ -1,6 +1,7 @@
 {
   "name": "pr-review",
-  "version": "1.0.0",
+  "version": "1.1.0",
+  "defaultModel": "sonnet",
   "description": "Multi-agent pull request review with confidence scoring and actionable feedback",
   "author": {
     "name": "Leo Miranda",

plugins/projman/.claude-plugin/plugin.json

@@ -1,6 +1,7 @@
 {
   "name": "projman",
-  "version": "3.2.0",
+  "version": "3.3.0",
+  "defaultModel": "sonnet",
   "description": "Sprint planning and project management with Gitea integration",
   "author": {
     "name": "Leo Miranda",

plugins/viz-platform/.claude-plugin/plugin.json

@@ -1,6 +1,7 @@
 {
   "name": "viz-platform",
-  "version": "1.0.0",
+  "version": "1.1.0",
+  "defaultModel": "sonnet",
   "description": "Visualization tools with Dash Mantine Components validation, Plotly charts, and theming",
   "author": {
     "name": "Leo Miranda",