feat(#2090): migrate cline onto imperative adapter + beforeTool/createAgentModel upgrades

Fold all hardcoded runtime === 'cline' / isCline branches in bin/install.js
into descriptor-driven runtime.hostBehaviors lookups (reapplyCommand,
frontmatterDialect, skipSharedHooksInstall, localTargetIsProjectRoot,
clineRulesSurface, localCommandsViaRules). Add cline-sdk-binding adapter
(ADR-1239 Phase D): UPGRADE 1 re-implements the .clinerules/hooks/PreToolUse
guard as a real AgentPlugin.hooks.beforeTool handler (fail-open, same
semantics); UPGRADE 2 wires DefaultGateway.createAgentModel params from
model_overrides/model_profile_overrides resolution (modelMode: active).
Install output is byte-identical (golden parity asserted for cline +
claude/cursor/codex/opencode).

capabilities/cline/capability.json

@@ -56,6 +56,14 @@
       "stateIO": "filesystem",
       "transport": "mcp",
       "runtime": "node"
+    },
+    "hostBehaviors": {
+      "reapplyCommand": "/gsd-update --reapply",
+      "frontmatterDialect": "cline",
+      "skipSharedHooksInstall": true,
+      "localTargetIsProjectRoot": true,
+      "clineRulesSurface": true,
+      "localCommandsViaRules": true
     }
   }
 }