refactor: route raw Bun.file/write/hash/which/spawn through runtime shims

Eliminates 19 unguarded `Bun.*` runtime call sites in the plugin bundle
that crashed with `ReferenceError: Bun is not defined` under Electron.

Per-tool-call hot paths (executed on every Read/Edit):
- src/tools/hashline-edit/hash-computation.ts: Bun.hash.xxHash32 → bunHashXxh32
- src/tools/hashline-edit/hashline-edit-executor.ts: 8 sites via bunFile/bunWrite
- src/hooks/hashline-read-enhancer/hook.ts: Bun.file → bunFile
- src/hooks/hashline-edit-diff-enhancer/hook.ts: 2 sites via bunFile

Plugin-load paths:
- src/hooks/claude-code-hooks/config.ts and config-loader.ts: Bun.file → bunFile
- src/features/claude-code-mcp-loader/loader.ts: Bun.file → bunFile
- src/features/claude-code-plugin-loader/mcp-server-loader.ts: Bun.file → bunFile
- src/features/team-mode/deps.ts: Bun.spawn → spawn shim
- src/hooks/session-notification-utils.ts: Bun.which → bunWhich, also drops
  the bare `declare const Bun` ambient declaration
- src/shared/binary-downloader.ts: Bun.write → bunWrite

Pure mechanical API swaps. No control-flow or signature changes.

src/features/claude-code-mcp-loader/loader.ts

@@ -11,6 +11,7 @@ import type {
 import { transformMcpServer } from "./transformer"
 import { log } from "../../shared/logger"
 import { shouldLoadMcpServer } from "./scope-filter"
+import { bunFile } from "../../shared/bun-file-shim"
 
 interface McpConfigPath {
   path: string
@@ -37,7 +38,7 @@ async function loadMcpConfigFile(
   }
 
   try {
-    const content = await Bun.file(filePath).text()
+    const content = await bunFile(filePath).text()
     return JSON.parse(content) as ClaudeCodeMcpConfig
   } catch (error) {
     log(`Failed to load MCP config from ${filePath}`, error)

src/features/claude-code-plugin-loader/mcp-server-loader.ts

@@ -7,6 +7,7 @@ import type { ClaudeCodeMcpConfig } from "../claude-code-mcp-loader/types"
 import { log } from "../../shared/logger"
 import type { LoadedPlugin } from "./types"
 import { resolvePluginPaths } from "./plugin-path-resolver"
+import { bunFile } from "../../shared/bun-file-shim"
 
 export async function loadPluginMcpServers(
   plugins: LoadedPlugin[],
@@ -18,7 +19,7 @@ export async function loadPluginMcpServers(
     if (!plugin.mcpPath || !existsSync(plugin.mcpPath)) continue
 
     try {
-      const content = await Bun.file(plugin.mcpPath).text()
+      const content = await bunFile(plugin.mcpPath).text()
       let config = JSON.parse(content) as ClaudeCodeMcpConfig
 
       config = resolvePluginPaths(config, plugin.installPath)

src/features/team-mode/deps.ts

@@ -1,4 +1,5 @@
 import type { TeamModeConfig } from "../../config/schema/team-mode"
+import { spawn } from "../../shared/bun-spawn-shim"
 
 export interface TeamModeDependencyReport {
   tmuxAvailable: boolean
@@ -20,7 +21,7 @@ export async function checkTeamModeDependencies(
 
 async function probeBinary(cmd: string, args: string[]): Promise<boolean> {
   try {
-    const proc = Bun.spawn({ cmd: [cmd, ...args], stdout: "pipe", stderr: "pipe" })
+    const proc = spawn({ cmd: [cmd, ...args], stdout: "pipe", stderr: "pipe" })
     const code = await proc.exited
     return code === 0
   } catch {

src/hooks/claude-code-hooks/config-loader.ts

@@ -3,6 +3,7 @@ import { join } from "path"
 import type { ClaudeHookEvent } from "./types"
 import { log } from "../../shared/logger"
 import { getOpenCodeConfigDir } from "../../shared"
+import { bunFile } from "../../shared/bun-file-shim"
 
 const CONFIG_CACHE_TTL_MS = 30_000
 
@@ -61,7 +62,7 @@ async function loadConfigFromPath(path: string): Promise<PluginExtendedConfig |
   }
 
   try {
-    const content = await Bun.file(path).text()
+    const content = await bunFile(path).text()
     return JSON.parse(content) as PluginExtendedConfig
   } catch (error) {
     log("Failed to load config", { path, error })

src/hooks/claude-code-hooks/config.ts

@@ -1,6 +1,7 @@
 import { join } from "path"
 import { existsSync } from "fs"
 import { getClaudeConfigDir } from "../../shared"
+import { bunFile } from "../../shared/bun-file-shim"
 import type { ClaudeHooksConfig, HookMatcher, HookAction } from "./types"
 
 const CONFIG_CACHE_TTL_MS = 30_000
@@ -126,7 +127,7 @@ export async function loadClaudeHooksConfig(
   for (const settingsPath of paths) {
     if (existsSync(settingsPath)) {
       try {
-        const content = await Bun.file(settingsPath).text()
+        const content = await bunFile(settingsPath).text()
         const settings = JSON.parse(content) as { hooks?: RawClaudeHooksConfig }
         if (settings.hooks) {
           const normalizedHooks = normalizeHooksConfig(settings.hooks)

src/hooks/hashline-edit-diff-enhancer/hook.ts

@@ -1,4 +1,5 @@
 import { log } from "../../shared"
+import { bunFile } from "../../shared/bun-file-shim"
 import { generateUnifiedDiff, countLineDiffs } from "../../tools/hashline-edit/diff-utils"
 
 interface HashlineEditDiffEnhancerConfig {
@@ -38,7 +39,7 @@ function extractFilePath(args: Record<string, unknown>): string | undefined {
 
 async function captureOldContent(filePath: string): Promise<string> {
 	try {
-		const file = Bun.file(filePath)
+		const file = bunFile(filePath)
 		if (await file.exists()) {
 			return await file.text()
 		}
@@ -79,7 +80,7 @@ export function createHashlineEditDiffEnhancerHook(config: HashlineEditDiffEnhan
 
 			let newContent: string
 			try {
-				newContent = await Bun.file(filePath).text()
+				newContent = await bunFile(filePath).text()
 			} catch {
 				log("[hashline-edit-diff-enhancer] failed to read new content", { filePath })
 				return

src/hooks/hashline-read-enhancer/hook.ts

@@ -1,4 +1,5 @@
 import type { PluginInput } from "@opencode-ai/plugin"
+import { bunFile } from "../../shared/bun-file-shim"
 import { computeLineHash } from "../../tools/hashline-edit/hash-computation"
 
 const WRITE_SUCCESS_MARKER = "File written successfully."
@@ -178,7 +179,7 @@ async function appendWriteHashlineOutput(output: { output: string; metadata: unk
     return
   }
 
-  const file = Bun.file(filePath)
+  const file = bunFile(filePath)
   if (!(await file.exists())) {
     return
   }

src/hooks/session-notification-utils.ts

@@ -1,14 +1,11 @@
 import { log } from "../shared/logger"
-
-declare const Bun: {
-  which(commandName: string): string | null
-}
+import { bunWhich } from "../shared/bun-which-shim"
 
 type Platform = "darwin" | "linux" | "win32" | "unsupported"
 
 async function findCommand(commandName: string): Promise<string | null> {
   try {
-    return Bun.which(commandName)
+    return bunWhich(commandName)
   } catch (error) {
     log("[session-notification] failed to resolve command path", {
       commandName,

src/shared/binary-downloader.ts

@@ -1,6 +1,7 @@
 import { chmodSync, existsSync, mkdirSync, unlinkSync } from "node:fs";
 import * as path from "node:path";
 import { spawn } from "./bun-spawn-shim";
+import { bunWrite } from "./bun-file-shim";
 import { validateArchiveEntries, type ArchiveEntry } from "./archive-entry-validator";
 import { extractZip } from "./zip-extractor";
 
@@ -26,7 +27,7 @@ export async function downloadArchive(downloadUrl: string, archivePath: string):
   }
 
   const arrayBuffer = await response.arrayBuffer();
-  await Bun.write(archivePath, arrayBuffer);
+  await bunWrite(archivePath, arrayBuffer);
 }
 
 export async function extractTarGz(

src/tools/hashline-edit/hash-computation.ts

@@ -1,12 +1,13 @@
 import { HASHLINE_DICT } from "./constants"
 import { createHashlineChunkFormatter } from "./hashline-chunk-formatter"
+import { bunHashXxh32 } from "../../shared/bun-hash-shim"
 
 const RE_SIGNIFICANT = /[\p{L}\p{N}]/u
 
 function computeNormalizedLineHash(lineNumber: number, normalizedContent: string): string {
   const stripped = normalizedContent
   const seed = RE_SIGNIFICANT.test(stripped) ? 0 : lineNumber
-  const hash = Bun.hash.xxHash32(stripped, seed)
+  const hash = bunHashXxh32(stripped, seed)
   const index = hash % 256
   return HASHLINE_DICT[index]
 }

src/tools/hashline-edit/hashline-edit-executor.ts

@@ -1,5 +1,6 @@
 import type { ToolContext } from "@opencode-ai/plugin/tool"
 import { publishToolMetadata } from "../../features/tool-metadata-store"
+import { bunFile, bunWrite } from "../../shared/bun-file-shim"
 import { applyHashlineEditsWithReport } from "./edit-operations"
 import { countLineDiffs, generateUnifiedDiff } from "./diff-utils"
 import { canonicalizeFileText, restoreFileText } from "./file-text-canonicalization"
@@ -94,7 +95,7 @@ export async function executeHashlineEditTool(args: HashlineEditArgs, context: T
 
     const edits = deleteMode ? [] : normalizeHashlineEdits(args.edits)
 
-    const file = Bun.file(filePath)
+    const file = bunFile(filePath)
     const exists = await file.exists()
     if (!exists && !deleteMode && !canCreateFromMissingFile(edits)) {
       return `Error: File not found: ${filePath}`
@@ -102,7 +103,7 @@ export async function executeHashlineEditTool(args: HashlineEditArgs, context: T
 
     if (deleteMode) {
       if (!exists) return `Error: File not found: ${filePath}`
-      await Bun.file(filePath).delete()
+      await bunFile(filePath).delete()
       return `Successfully deleted ${filePath}`
     }
 
@@ -122,11 +123,11 @@ export async function executeHashlineEditTool(args: HashlineEditArgs, context: T
 
     const writeContent = restoreFileText(canonicalNewContent, oldEnvelope)
 
-    await Bun.write(filePath, writeContent)
+    await bunWrite(filePath, writeContent)
 
     if (pluginCtx?.client) {
       await runFormattersForFile(pluginCtx.client as FormatterClient, context.directory, filePath)
-      const formattedContent = Buffer.from(await Bun.file(filePath).arrayBuffer()).toString("utf8")
+      const formattedContent = Buffer.from(await bunFile(filePath).arrayBuffer()).toString("utf8")
       if (formattedContent !== writeContent) {
         const formattedEnvelope = canonicalizeFileText(formattedContent)
         const formattedMeta = buildSuccessMeta(
@@ -138,8 +139,8 @@ export async function executeHashlineEditTool(args: HashlineEditArgs, context: T
         )
         await publishToolMetadata(metadataContext, formattedMeta)
         if (rename && rename !== filePath) {
-          await Bun.write(rename, formattedContent)
-          await Bun.file(filePath).delete()
+          await bunWrite(rename, formattedContent)
+          await bunFile(filePath).delete()
           return `Moved ${filePath} to ${rename}`
         }
         return `Updated ${filePath}`
@@ -147,8 +148,8 @@ export async function executeHashlineEditTool(args: HashlineEditArgs, context: T
     }
 
     if (rename && rename !== filePath) {
-      await Bun.write(rename, writeContent)
-      await Bun.file(filePath).delete()
+      await bunWrite(rename, writeContent)
+      await bunFile(filePath).delete()
     }
 
     const effectivePath = rename && rename !== filePath ? rename : filePath