test(keyword-detector): capture mode prompt baselines

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

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

src/hooks/keyword-detector/mode-prompt-baseline.test.ts

@@ -0,0 +1,96 @@
+import { describe, expect, test } from "bun:test"
+import { createHash } from "node:crypto"
+import { dirname, join } from "node:path"
+import { fileURLToPath } from "node:url"
+import { ANALYZE_MESSAGE, HYPERPLAN_MESSAGE, SEARCH_MESSAGE, TEAM_MESSAGE } from "./constants"
+
+type PromptBaseline = {
+  readonly name: string
+  readonly message: string
+  readonly sha256: string
+  readonly byteLength: number
+}
+
+type ShimBaseline = {
+  readonly name: string
+  readonly filePath: string
+}
+
+const MODE_PROMPT_BASELINES: readonly PromptBaseline[] = [
+  {
+    name: "search",
+    message: SEARCH_MESSAGE,
+    sha256: "aa38d1011edcf083394441321564330661868411ec13b575e5994812fae27f62",
+    byteLength: 311,
+  },
+  {
+    name: "analyze",
+    message: ANALYZE_MESSAGE,
+    sha256: "63f9de6f7afb67ab68bc4abcc7e78c8450a6ce556378a7a5d2b9061a3c519d7f",
+    byteLength: 865,
+  },
+  {
+    name: "team",
+    message: TEAM_MESSAGE,
+    sha256: "21fd4110835ce380e307cf29e132753b04a58758b86cfaaf5dda26e0e3193d69",
+    byteLength: 614,
+  },
+  {
+    name: "hyperplan",
+    message: HYPERPLAN_MESSAGE,
+    sha256: "cea6f378370c736909be99bd9a66a06db1e4819848336dd7951298e949270ced",
+    byteLength: 1500,
+  },
+]
+
+const KEYWORD_DETECTOR_DIR = dirname(fileURLToPath(import.meta.url))
+
+const MODE_SHIMS: readonly ShimBaseline[] = [
+  { name: "search", filePath: join(KEYWORD_DETECTOR_DIR, "search", "default.ts") },
+  { name: "analyze", filePath: join(KEYWORD_DETECTOR_DIR, "analyze", "default.ts") },
+  { name: "team", filePath: join(KEYWORD_DETECTOR_DIR, "team", "default.ts") },
+  { name: "hyperplan", filePath: join(KEYWORD_DETECTOR_DIR, "hyperplan", "default.ts") },
+]
+
+describe("keyword-detector mode prompt baselines", () => {
+  test("#given captured prompt baselines #then each mode message keeps the same bytes", () => {
+    for (const baseline of MODE_PROMPT_BASELINES) {
+      expect(hashPrompt(baseline.message), baseline.name).toBe(baseline.sha256)
+      expect(Buffer.byteLength(baseline.message, "utf8"), baseline.name).toBe(baseline.byteLength)
+    }
+  })
+
+  test("#given migrated mode shims #then each shim stays within the LOC ceiling", async () => {
+    for (const shim of MODE_SHIMS) {
+      const source = await Bun.file(shim.filePath).text()
+
+      expect(countPureLoc(source), shim.name).toBeLessThanOrEqual(20)
+    }
+  })
+})
+
+function hashPrompt(prompt: string): string {
+  return createHash("sha256").update(prompt, "utf8").digest("hex")
+}
+
+function countPureLoc(source: string): number {
+  let pureLoc = 0
+  let insideBlockComment = false
+
+  for (const rawLine of source.split("\n")) {
+    const line = rawLine.trim()
+    if (line.length === 0) continue
+    if (insideBlockComment) {
+      insideBlockComment = !line.includes("*/")
+      continue
+    }
+    if (line.startsWith("/*")) {
+      insideBlockComment = !line.includes("*/")
+      continue
+    }
+    if (line.startsWith("//")) continue
+    pureLoc += 1
+  }
+
+  return pureLoc
+}