refactor(mode-prompts): migrate search prompt

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

packages/prompts-core/prompts/mode/search.md

@@ -0,0 +1,6 @@
+[search-mode]
+MAXIMIZE SEARCH EFFORT. Launch multiple background agents IN PARALLEL:
+- explore agents (codebase patterns, file structures, ast-grep)
+- librarian agents (remote repos, official docs, GitHub examples)
+Plus direct tools: Grep, ripgrep (rg), ast-grep (sg)
+NEVER stop at first result - be exhaustive.

packages/prompts-core/src/index.ts

@@ -9,3 +9,4 @@ export type {
 export { resolveVariant } from "./variant-resolver"
 export type { ResolveVariantInput } from "./variant-resolver"
 export { loadPrompt, PromptFileNotFoundError, PromptPathTraversalError } from "./loader"
+export { SEARCH_MODE_PROMPT } from "./mode-prompts"

packages/prompts-core/src/mode-prompts.ts

@@ -0,0 +1,7 @@
+import searchModePrompt from "../prompts/mode/search.md" with { type: "text" }
+
+export const SEARCH_MODE_PROMPT = stripFinalLineFeed(searchModePrompt)
+
+function stripFinalLineFeed(prompt: string): string {
+  return prompt.endsWith("\n") ? prompt.slice(0, -1) : prompt
+}

src/hooks/keyword-detector/search/default.ts

@@ -1,3 +1,5 @@
+import { SEARCH_MODE_PROMPT } from "@oh-my-opencode/prompts-core"
+
 /**
  * Search mode keyword detector.
  *
@@ -12,9 +14,4 @@
 export const SEARCH_PATTERN =
   /\b(search|find|locate|lookup|look\s*up|explore|discover|scan|grep|query|browse|detect|trace|seek|track|pinpoint|hunt)\b|where\s+is|show\s+me|list\s+all|검색|찾아|탐색|조회|스캔|서치|뒤져|찾기|어디|추적|탐지|찾아봐|찾아내|보여줘|목록|検索|探して|見つけて|サーチ|探索|スキャン|どこ|発見|捜索|見つけ出す|一覧|搜索|查找|寻找|查询|检索|定位|扫描|发现|在哪里|找出来|列出|tìm kiếm|tra cứu|định vị|quét|phát hiện|truy tìm|tìm ra|ở đâu|liệt kê/i
 
-export const SEARCH_MESSAGE = `[search-mode]
-MAXIMIZE SEARCH EFFORT. Launch multiple background agents IN PARALLEL:
-- explore agents (codebase patterns, file structures, ast-grep)
-- librarian agents (remote repos, official docs, GitHub examples)
-Plus direct tools: Grep, ripgrep (rg), ast-grep (sg)
-NEVER stop at first result - be exhaustive.`
+export const SEARCH_MESSAGE = SEARCH_MODE_PROMPT