feat: add multi-repo cloning, remove dynamic/serverless mode

Add githubRepos list field for cloning multiple repositories into a
single dev container with multi-root workspace file generation.
Remove the unused dynamic deployment mode (Knative, routing proxy,
serverless scripts) to simplify the chart to persistent-only.
Fix release workflow cache-to setting that violated the no-cache policy.

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

chart/values.schema.json

@@ -32,14 +32,14 @@
       },
       "required": ["repository", "tag"]
     },
-    "deploymentMode": {
-      "type": "string",
-      "enum": ["persistent", "dynamic"],
-      "description": "Deployment mode: persistent (PVC-based) or dynamic (Knative serverless)"
-    },
     "githubRepo": {
       "type": "string",
-      "description": "GitHub repository URL to clone (required in persistent mode, ignored in dynamic mode)"
+      "description": "GitHub repository URL to clone into /workspace"
+    },
+    "githubRepos": {
+      "type": "array",
+      "items": { "type": "string" },
+      "description": "Multiple GitHub repository URLs to clone (takes precedence over githubRepo)"
     },
     "fileManager": {
       "type": "object",
@@ -59,75 +59,6 @@
       },
       "required": ["enabled"]
     },
-    "dynamic": {
-      "type": "object",
-      "description": "Configuration for dynamic (serverless) deployment mode",
-      "properties": {
-        "knative": {
-          "type": "object",
-          "properties": {
-            "minScale": { "type": "integer", "minimum": 0 },
-            "maxScale": { "type": "integer", "minimum": 1 },
-            "target": { "type": "integer", "minimum": 1 },
-            "scaleToZeroGracePeriod": { "type": "string" },
-            "timeoutSeconds": { "type": "integer", "minimum": 60 },
-            "resources": {
-              "type": "object",
-              "properties": {
-                "requests": { "$ref": "#/$defs/resourceSpec" },
-                "limits": { "$ref": "#/$defs/resourceSpec" }
-              }
-            }
-          }
-        },
-        "routingProxy": {
-          "type": "object",
-          "properties": {
-            "enabled": { "type": "boolean" },
-            "replicas": { "type": "integer", "minimum": 1 },
-            "image": {
-              "type": "object",
-              "properties": {
-                "repository": { "type": "string" },
-                "tag": { "type": "string" },
-                "pullPolicy": { "type": "string", "enum": ["Always", "IfNotPresent", "Never"] }
-              }
-            },
-            "resources": {
-              "type": "object",
-              "properties": {
-                "requests": { "$ref": "#/$defs/resourceSpec" },
-                "limits": { "$ref": "#/$defs/resourceSpec" }
-              }
-            }
-          }
-        },
-        "ingress": {
-          "type": "object",
-          "properties": {
-            "enabled": { "type": "boolean" },
-            "className": { "type": "string" },
-            "host": { "type": "string" },
-            "tls": {
-              "type": "object",
-              "properties": {
-                "enabled": { "type": "boolean" },
-                "secretName": { "type": "string" },
-                "issuer": { "type": "string" }
-              }
-            },
-            "authentik": {
-              "type": "object",
-              "properties": {
-                "enabled": { "type": "boolean" },
-                "authUrl": { "type": "string" },
-                "signIn": { "type": "string" }
-              }
-            }
-          }
-        }
-      }
-    },
     "ide": {
       "type": "object",
       "properties": {