fix(background): Wave 2 - fix interrupt status checks, display text, error recovery grace, LSP JSONC

- fix(background): include "interrupt" status in all terminal status checks (3 files)
- fix(background): display "INTERRUPTED" instead of "CANCELLED" for interrupted tasks
- fix(cli): add error recovery grace period in poll-for-completion
- fix(lsp): use JSONC parser for config loading to support comments

All changes verified with tests and typecheck.

src/tools/lsp/server-config-loader.test.ts

@@ -0,0 +1,39 @@
+import { describe, it, expect } from "bun:test"
+import { writeFileSync, unlinkSync } from "fs"
+import { join } from "path"
+import { tmpdir } from "os"
+import { loadJsonFile } from "./server-config-loader"
+
+describe("loadJsonFile", () => {
+  it("parses JSONC config files with comments correctly", () => {
+    // given
+    const testData = {
+      lsp: {
+        typescript: {
+          command: ["tsserver"],
+          extensions: [".ts", ".tsx"]
+        }
+      }
+    }
+    const jsoncContent = `{
+  // LSP configuration for TypeScript
+  "lsp": {
+    "typescript": {
+      "command": ["tsserver"],
+      "extensions": [".ts", ".tsx"] // TypeScript extensions
+    }
+  }
+}`
+    const tempPath = join(tmpdir(), "test-config.jsonc")
+    writeFileSync(tempPath, jsoncContent, "utf-8")
+
+    // when
+    const result = loadJsonFile<typeof testData>(tempPath)
+
+    // then
+    expect(result).toEqual(testData)
+
+    // cleanup
+    unlinkSync(tempPath)
+  })
+})