[Platform] Add symfony/ai-agent dependency for bridges with OutputProcessors

Bridges with TokenOutputProcessor or SearchResultProcessor need
symfony/ai-agent as a dependency.

Affected bridges:
- Anthropic
- DeepSeek
- Gemini
- Mistral
- OpenAi
- Perplexity
- VertexAi

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Author: OskarStark

src/platform/src/Bridge/Anthropic/composer.json

@@ -20,6 +20,7 @@
     ],
     "require": {
         "php": ">=8.2",
+        "symfony/ai-agent": "@dev",
         "symfony/ai-platform": "@dev"
     },
     "require-dev": {

src/platform/src/Bridge/DeepSeek/composer.json

@@ -25,6 +25,7 @@
   ],
   "require": {
     "php": ">=8.2",
+    "symfony/ai-agent": "@dev",
     "symfony/ai-platform": "@dev"
   },
   "require-dev": {

src/platform/src/Bridge/Gemini/composer.json

@@ -20,6 +20,7 @@
     ],
     "require": {
         "php": ">=8.2",
+        "symfony/ai-agent": "@dev",
         "symfony/ai-platform": "@dev"
     },
     "require-dev": {

src/platform/src/Bridge/Mistral/composer.json

@@ -20,6 +20,7 @@
     ],
     "require": {
         "php": ">=8.2",
+        "symfony/ai-agent": "@dev",
         "symfony/ai-platform": "@dev"
     },
     "require-dev": {

src/platform/src/Bridge/OpenAi/composer.json

@@ -31,6 +31,7 @@
   ],
   "require": {
     "php": ">=8.2",
+    "symfony/ai-agent": "@dev",
     "symfony/ai-platform": "@dev"
   },
   "require-dev": {

src/platform/src/Bridge/Perplexity/composer.json

@@ -20,6 +20,7 @@
     ],
     "require": {
         "php": ">=8.2",
+        "symfony/ai-agent": "@dev",
         "symfony/ai-platform": "@dev"
     },
     "require-dev": {

src/platform/src/Bridge/VertexAi/composer.json

@@ -26,8 +26,9 @@
   ],
   "require": {
     "php": ">=8.2",
-    "symfony/ai-platform": "@dev",
-    "google/auth": "^1.47"
+    "google/auth": "^1.47",
+    "symfony/ai-agent": "@dev",
+    "symfony/ai-platform": "@dev"
   },
   "require-dev": {
     "phpunit/phpunit": "^11.5.13"