style(cso): format lib/cso TypeScript with pinned Prettier

Mechanical reformat only. Minified transpile output is byte-identical for
21 of 22 files; witness.ts differs only in three regex flag orders
(/mi -> /im), which JavaScript canonicalizes. Source-text assertions over
lib/cso now compare whitespace-insensitively with the same tokens.

bun.lock

@@ -17,6 +17,7 @@
       "devDependencies": {
         "@anthropic-ai/claude-agent-sdk": "0.2.117",
         "@anthropic-ai/sdk": "^0.78.0",
+        "prettier": "3.9.9",
         "xterm": "^5.3.0",
         "xterm-addon-fit": "^0.8.0",
       },
@@ -425,6 +426,8 @@
 
     "playwright-core": ["playwright-core@1.62.1", "", { "bin": { "playwright-core": "cli.js" } }, "sha512-wPYSwEBJY9GHraISXqyqtx0na0LpO3XEX7jNDhntbex7tzUS7kLnZsOlFruFJB4Hi/rhDMjXGqHewDZ68nYZVw=="],
 
+    "prettier": ["prettier@3.9.9", "", { "bin": { "prettier": "bin/prettier.cjs" } }, "sha512-Z/CJHIkdujO/OtN7nXUii0Rf3VT5SRuhjBA82Xvu2XhBUgX3nhP67T0LHceBdQLex7OOFGTox+Q5Yg8Jk2Qivg=="],
+
     "process": ["process@0.11.10", "", {}, "sha512-cdGef/drWFoydD1JsMzuFf8100nZl+GT+yacc2bEced5f9Rjk4z+WtFUTBu9PhOi9j/jfmBPu0mMEY4wIdAF8A=="],
 
     "process-nextick-args": ["process-nextick-args@2.0.1", "", {}, "sha512-3ouUOpQhtgrbOa17J7+uxOTpITYWaGP7/AhoR3+A+/1e9skrzelGi/dXzEYyvbxubEF6Wn2ypscTKiKJFFn1ag=="],