feat(multimodal-looker): restrict to read-only tool access

Use createAgentToolAllowlist to allow only 'read' tool for multimodal-looker agent.
Previously denied write/edit/bash but allowed other tools.
Now uses wildcard deny pattern (*: deny) with explicit read allow.

- Add createAgentToolAllowlist function for allowlist-based restrictions
- Support legacy fallback for older OpenCode versions
- Add 4 test cases covering both permission systems

src/shared/permission-compat.test.ts

@@ -1,6 +1,7 @@
 import { describe, test, expect, beforeEach, afterEach } from "bun:test"
 import {
   createAgentToolRestrictions,
+  createAgentToolAllowlist,
   migrateToolsToPermission,
   migratePermissionToTools,
   migrateAgentConfig,
@@ -57,6 +58,63 @@ describe("permission-compat", () => {
     })
   })
 
+  describe("createAgentToolAllowlist", () => {
+    test("returns wildcard deny with explicit allow for v1.1.1+", () => {
+      // #given version is 1.1.1
+      setVersionCache("1.1.1")
+
+      // #when creating allowlist
+      const result = createAgentToolAllowlist(["read"])
+
+      // #then returns wildcard deny with read allow
+      expect(result).toEqual({
+        permission: { "*": "deny", read: "allow" },
+      })
+    })
+
+    test("returns wildcard deny with multiple allows for v1.1.1+", () => {
+      // #given version is 1.1.1
+      setVersionCache("1.1.1")
+
+      // #when creating allowlist with multiple tools
+      const result = createAgentToolAllowlist(["read", "glob"])
+
+      // #then returns wildcard deny with both allows
+      expect(result).toEqual({
+        permission: { "*": "deny", read: "allow", glob: "allow" },
+      })
+    })
+
+    test("returns explicit deny list for old versions", () => {
+      // #given version is below 1.1.1
+      setVersionCache("1.0.150")
+
+      // #when creating allowlist
+      const result = createAgentToolAllowlist(["read"])
+
+      // #then returns tools format with common tools denied except read
+      expect(result).toHaveProperty("tools")
+      const tools = (result as { tools: Record<string, boolean> }).tools
+      expect(tools.write).toBe(false)
+      expect(tools.edit).toBe(false)
+      expect(tools.bash).toBe(false)
+      expect(tools.read).toBeUndefined()
+    })
+
+    test("excludes allowed tools from legacy deny list", () => {
+      // #given version is below 1.1.1
+      setVersionCache("1.0.150")
+
+      // #when creating allowlist with glob
+      const result = createAgentToolAllowlist(["read", "glob"])
+
+      // #then glob is not in deny list
+      const tools = (result as { tools: Record<string, boolean> }).tools
+      expect(tools.glob).toBeUndefined()
+      expect(tools.write).toBe(false)
+    })
+  })
+
   describe("migrateToolsToPermission", () => {
     test("converts boolean tools to permission values", () => {
       // #given tools config

src/shared/permission-compat.ts

@@ -30,6 +30,69 @@ export function createAgentToolRestrictions(
   }
 }
 
+/**
+ * Common tools that should be denied when using allowlist approach.
+ * Used for legacy fallback when `*: deny` pattern is not supported.
+ */
+const COMMON_TOOLS_TO_DENY = [
+  "write",
+  "edit",
+  "bash",
+  "task",
+  "sisyphus_task",
+  "call_omo_agent",
+  "webfetch",
+  "glob",
+  "grep",
+  "lsp_diagnostics",
+  "lsp_prepare_rename",
+  "lsp_rename",
+  "ast_grep_search",
+  "ast_grep_replace",
+  "session_list",
+  "session_read",
+  "session_search",
+  "session_info",
+  "background_output",
+  "background_cancel",
+  "skill",
+  "skill_mcp",
+  "look_at",
+  "todowrite",
+  "todoread",
+  "interactive_bash",
+] as const
+
+/**
+ * Creates tool restrictions that ONLY allow specified tools.
+ * All other tools are denied by default.
+ *
+ * Uses `*: deny` pattern for new permission system,
+ * falls back to explicit deny list for legacy systems.
+ */
+export function createAgentToolAllowlist(
+  allowTools: string[]
+): VersionAwareRestrictions {
+  if (supportsNewPermissionSystem()) {
+    return {
+      permission: {
+        "*": "deny" as const,
+        ...Object.fromEntries(
+          allowTools.map((tool) => [tool, "allow" as const])
+        ),
+      },
+    }
+  }
+
+  // Legacy fallback: explicitly deny common tools except allowed ones
+  const allowSet = new Set(allowTools)
+  const denyTools = COMMON_TOOLS_TO_DENY.filter((tool) => !allowSet.has(tool))
+
+  return {
+    tools: Object.fromEntries(denyTools.map((tool) => [tool, false])),
+  }
+}
+
 export function migrateToolsToPermission(
   tools: Record<string, boolean>
 ): Record<string, PermissionValue> {