core: effectify CLI account commands with tagged PollResult union

- Rewrite all account CLI commands (login, logout, switch, orgs) as
  Effect.fn with AccountService accessed directly via yield*
- Convert PollResult from plain object union to Schema.TaggedClass
  variants with Schema.Union and Match.valueTags for exhaustive matching
- Add recursive poll function for device auth flow (stack-safe via
  Effect trampolining)
- Add shared Effect runtime at src/effect/runtime.ts
- Add Effect wrappers for @clack/prompts at src/cli/effect/prompt.ts
- Add @effect/language-service TS plugin for editor support
- Refactor repo tests to use testEffect helper with Layer-based setup
- Parallelize org fetching in orgs command

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

bun.lock

@@ -350,6 +350,7 @@
       },
       "devDependencies": {
         "@babel/core": "7.28.4",
+        "@effect/language-service": "0.78.0",
         "@octokit/webhooks-types": "7.6.1",
         "@opencode-ai/script": "workspace:*",
         "@parcel/watcher-darwin-arm64": "2.5.1",
@@ -915,6 +916,8 @@
 
     "@drizzle-team/brocli": ["@drizzle-team/brocli@0.11.0", "", {}, "sha512-hD3pekGiPg0WPCCGAZmusBBJsDqGUR66Y452YgQsZOnkdQ7ViEPKuyP4huUGEZQefp8g34RRodXYmJ2TbCH+tg=="],
 
+    "@effect/language-service": ["@effect/language-service@0.78.0", "", { "bin": { "effect-language-service": "cli.js" } }, "sha512-dEYMhvhKFhikXpXjOlcByRKOU34xFeZbZcOuVTeWTQmjmZ/ZF4K3z0Ku6vL4cWKC8RRIB5di+ix18Y4f9ey5Dg=="],
+
     "@emmetio/abbreviation": ["@emmetio/abbreviation@2.3.3", "", { "dependencies": { "@emmetio/scanner": "^1.0.4" } }, "sha512-mgv58UrU3rh4YgbE/TzgLQwJ3pFsHHhCLqY20aJq+9comytTXUDNGG/SMtSeMJdkpxgXSXunBGLD8Boka3JyVA=="],
 
     "@emmetio/css-abbreviation": ["@emmetio/css-abbreviation@2.1.8", "", { "dependencies": { "@emmetio/scanner": "^1.0.4" } }, "sha512-s9yjhJ6saOO/uk1V74eifykk2CBYi01STTK3WlXWGOepyKa23ymJ053+DNQjpFcy1ingpaO7AxCcwLvHFY9tuw=="],