core: consolidate shared infrastructure into core package

Moves effect logging, observability, runtime utilities, flags, installation
version info, and process utilities from opencode to core package. This
enables better code sharing across packages and establishes core as the
single source of truth for foundational utilities.

All internal imports updated to use @opencode-ai/core paths for consistency.

packages/core/src/flag/flag.ts

@@ -0,0 +1,107 @@
+import { Config } from "effect"
+
+function truthy(key: string) {
+  const value = process.env[key]?.toLowerCase()
+  return value === "true" || value === "1"
+}
+
+function falsy(key: string) {
+  const value = process.env[key]?.toLowerCase()
+  return value === "false" || value === "0"
+}
+
+function number(key: string) {
+  const value = process.env[key]
+  if (!value) return undefined
+  const parsed = Number(value)
+  return Number.isInteger(parsed) && parsed > 0 ? parsed : undefined
+}
+
+const OPENCODE_EXPERIMENTAL = truthy("OPENCODE_EXPERIMENTAL")
+const OPENCODE_DISABLE_CLAUDE_CODE = truthy("OPENCODE_DISABLE_CLAUDE_CODE")
+const OPENCODE_DISABLE_CLAUDE_CODE_SKILLS =
+  OPENCODE_DISABLE_CLAUDE_CODE || truthy("OPENCODE_DISABLE_CLAUDE_CODE_SKILLS")
+const copy = process.env["OPENCODE_EXPERIMENTAL_DISABLE_COPY_ON_SELECT"]
+
+export const Flag = {
+  OTEL_EXPORTER_OTLP_ENDPOINT: process.env["OTEL_EXPORTER_OTLP_ENDPOINT"],
+  OTEL_EXPORTER_OTLP_HEADERS: process.env["OTEL_EXPORTER_OTLP_HEADERS"],
+
+  OPENCODE_AUTO_SHARE: truthy("OPENCODE_AUTO_SHARE"),
+  OPENCODE_AUTO_HEAP_SNAPSHOT: truthy("OPENCODE_AUTO_HEAP_SNAPSHOT"),
+  OPENCODE_GIT_BASH_PATH: process.env["OPENCODE_GIT_BASH_PATH"],
+  OPENCODE_CONFIG: process.env["OPENCODE_CONFIG"],
+  OPENCODE_CONFIG_CONTENT: process.env["OPENCODE_CONFIG_CONTENT"],
+  OPENCODE_DISABLE_AUTOUPDATE: truthy("OPENCODE_DISABLE_AUTOUPDATE"),
+  OPENCODE_ALWAYS_NOTIFY_UPDATE: truthy("OPENCODE_ALWAYS_NOTIFY_UPDATE"),
+  OPENCODE_DISABLE_PRUNE: truthy("OPENCODE_DISABLE_PRUNE"),
+  OPENCODE_DISABLE_TERMINAL_TITLE: truthy("OPENCODE_DISABLE_TERMINAL_TITLE"),
+  OPENCODE_SHOW_TTFD: truthy("OPENCODE_SHOW_TTFD"),
+  OPENCODE_PERMISSION: process.env["OPENCODE_PERMISSION"],
+  OPENCODE_DISABLE_DEFAULT_PLUGINS: truthy("OPENCODE_DISABLE_DEFAULT_PLUGINS"),
+  OPENCODE_DISABLE_LSP_DOWNLOAD: truthy("OPENCODE_DISABLE_LSP_DOWNLOAD"),
+  OPENCODE_ENABLE_EXPERIMENTAL_MODELS: truthy("OPENCODE_ENABLE_EXPERIMENTAL_MODELS"),
+  OPENCODE_DISABLE_AUTOCOMPACT: truthy("OPENCODE_DISABLE_AUTOCOMPACT"),
+  OPENCODE_DISABLE_MODELS_FETCH: truthy("OPENCODE_DISABLE_MODELS_FETCH"),
+  OPENCODE_DISABLE_MOUSE: truthy("OPENCODE_DISABLE_MOUSE"),
+  OPENCODE_DISABLE_CLAUDE_CODE,
+  OPENCODE_DISABLE_CLAUDE_CODE_PROMPT: OPENCODE_DISABLE_CLAUDE_CODE || truthy("OPENCODE_DISABLE_CLAUDE_CODE_PROMPT"),
+  OPENCODE_DISABLE_CLAUDE_CODE_SKILLS,
+  OPENCODE_DISABLE_EXTERNAL_SKILLS: OPENCODE_DISABLE_CLAUDE_CODE_SKILLS || truthy("OPENCODE_DISABLE_EXTERNAL_SKILLS"),
+  OPENCODE_FAKE_VCS: process.env["OPENCODE_FAKE_VCS"],
+  OPENCODE_SERVER_PASSWORD: process.env["OPENCODE_SERVER_PASSWORD"],
+  OPENCODE_SERVER_USERNAME: process.env["OPENCODE_SERVER_USERNAME"],
+  OPENCODE_ENABLE_QUESTION_TOOL: truthy("OPENCODE_ENABLE_QUESTION_TOOL"),
+
+  // Experimental
+  OPENCODE_EXPERIMENTAL,
+  OPENCODE_EXPERIMENTAL_FILEWATCHER: Config.boolean("OPENCODE_EXPERIMENTAL_FILEWATCHER").pipe(
+    Config.withDefault(false),
+  ),
+  OPENCODE_EXPERIMENTAL_DISABLE_FILEWATCHER: Config.boolean("OPENCODE_EXPERIMENTAL_DISABLE_FILEWATCHER").pipe(
+    Config.withDefault(false),
+  ),
+  OPENCODE_EXPERIMENTAL_ICON_DISCOVERY: OPENCODE_EXPERIMENTAL || truthy("OPENCODE_EXPERIMENTAL_ICON_DISCOVERY"),
+  OPENCODE_EXPERIMENTAL_DISABLE_COPY_ON_SELECT:
+    copy === undefined ? process.platform === "win32" : truthy("OPENCODE_EXPERIMENTAL_DISABLE_COPY_ON_SELECT"),
+  OPENCODE_ENABLE_EXA: truthy("OPENCODE_ENABLE_EXA") || OPENCODE_EXPERIMENTAL || truthy("OPENCODE_EXPERIMENTAL_EXA"),
+  OPENCODE_EXPERIMENTAL_BASH_DEFAULT_TIMEOUT_MS: number("OPENCODE_EXPERIMENTAL_BASH_DEFAULT_TIMEOUT_MS"),
+  OPENCODE_EXPERIMENTAL_OUTPUT_TOKEN_MAX: number("OPENCODE_EXPERIMENTAL_OUTPUT_TOKEN_MAX"),
+  OPENCODE_EXPERIMENTAL_OXFMT: OPENCODE_EXPERIMENTAL || truthy("OPENCODE_EXPERIMENTAL_OXFMT"),
+  OPENCODE_EXPERIMENTAL_LSP_TY: truthy("OPENCODE_EXPERIMENTAL_LSP_TY"),
+  OPENCODE_EXPERIMENTAL_LSP_TOOL: OPENCODE_EXPERIMENTAL || truthy("OPENCODE_EXPERIMENTAL_LSP_TOOL"),
+  OPENCODE_EXPERIMENTAL_PLAN_MODE: OPENCODE_EXPERIMENTAL || truthy("OPENCODE_EXPERIMENTAL_PLAN_MODE"),
+  OPENCODE_EXPERIMENTAL_MARKDOWN: !falsy("OPENCODE_EXPERIMENTAL_MARKDOWN"),
+  OPENCODE_MODELS_URL: process.env["OPENCODE_MODELS_URL"],
+  OPENCODE_MODELS_PATH: process.env["OPENCODE_MODELS_PATH"],
+  OPENCODE_DISABLE_EMBEDDED_WEB_UI: truthy("OPENCODE_DISABLE_EMBEDDED_WEB_UI"),
+  OPENCODE_DB: process.env["OPENCODE_DB"],
+  OPENCODE_DISABLE_CHANNEL_DB: truthy("OPENCODE_DISABLE_CHANNEL_DB"),
+  OPENCODE_SKIP_MIGRATIONS: truthy("OPENCODE_SKIP_MIGRATIONS"),
+  OPENCODE_STRICT_CONFIG_DEPS: truthy("OPENCODE_STRICT_CONFIG_DEPS"),
+
+  OPENCODE_WORKSPACE_ID: process.env["OPENCODE_WORKSPACE_ID"],
+  OPENCODE_EXPERIMENTAL_HTTPAPI: truthy("OPENCODE_EXPERIMENTAL_HTTPAPI"),
+  OPENCODE_EXPERIMENTAL_WORKSPACES: OPENCODE_EXPERIMENTAL || truthy("OPENCODE_EXPERIMENTAL_WORKSPACES"),
+
+  // Evaluated at access time (not module load) because tests, the CLI, and
+  // external tooling set these env vars at runtime.
+  get OPENCODE_DISABLE_PROJECT_CONFIG() {
+    return truthy("OPENCODE_DISABLE_PROJECT_CONFIG")
+  },
+  get OPENCODE_TUI_CONFIG() {
+    return process.env["OPENCODE_TUI_CONFIG"]
+  },
+  get OPENCODE_CONFIG_DIR() {
+    return process.env["OPENCODE_CONFIG_DIR"]
+  },
+  get OPENCODE_PURE() {
+    return truthy("OPENCODE_PURE")
+  },
+  get OPENCODE_PLUGIN_META_FILE() {
+    return process.env["OPENCODE_PLUGIN_META_FILE"]
+  },
+  get OPENCODE_CLIENT() {
+    return process.env["OPENCODE_CLIENT"] ?? "cli"
+  },
+}