docs: add missing @fileoverview headers to 26 modules

Brings every module under src/ (excluding external/ and types/) to
@fileoverview coverage. Files updated span constants/, env/, argv/,
and the core git.ts, ipc.ts, promise-queue.ts, utils/get-ipc.ts.

Each header is a short 2-4 line summary describing what the module
is for and what belongs in it, modeled after the existing style in
src/spawn.ts and src/http-request.ts. ipc.ts absorbed its previous
prose-heavy leading comment into a concise @fileoverview block.

Author: jdalton

src/argv/flags.ts

@@ -1,6 +1,8 @@
 /**
- * Common flag utilities for Socket CLI applications.
- * Provides consistent flag checking across all Socket projects.
+ * @fileoverview Common flag utilities for Socket CLI applications.
+ * Provides consistent flag checking (quiet, silent, verbose, debug, dry-run,
+ * etc.) across Socket projects, accepting either parsed flag objects or raw
+ * argv arrays.
  */
 
 /**

src/argv/parse.ts

@@ -1,6 +1,7 @@
 /**
- * Argument parsing utilities for CLI applications.
- * Uses yargs-parser internally for robust argument parsing with Node.js parseArgs-compatible API.
+ * @fileoverview Argument parsing utilities for CLI applications.
+ * Wraps the vendored yargs-parser with a Node.js parseArgs-compatible surface
+ * for booleans, strings, arrays, aliases, defaults, and coercion.
  */
 
 import process from 'node:process'

src/constants/agents.ts

@@ -1,6 +1,7 @@
 /**
- * Package manager agent constants.
- * Agent names, lockfile names, registry URLs, and configuration field names.
+ * @fileoverview Package manager agent constants.
+ * Exports agent names (npm/pnpm/yarn/bun/vlt/npx), lockfile names, registry
+ * URLs, and resolved npm binary paths used across Socket tooling.
  */
 
 import which from '../external/which'

src/constants/core.ts

@@ -1,6 +1,8 @@
 /**
- * Core primitives and fundamental constants.
- * Goal: Minimize this module by finding proper semantic homes for all constants.
+ * @fileoverview Core primitives and fundamental constants.
+ * Holds sentinels, unknown/empty tokens, the internals symbol, and a few
+ * shared env-var name strings. Intentionally kept small - prefer moving
+ * constants to a more specific `src/constants/*` module when possible.
  */
 
 // Internal implementation symbol.

src/constants/encoding.ts

@@ -1,5 +1,7 @@
 /**
- * Character encodings and character codes.
+ * @fileoverview Character encoding and character code constants.
+ * Exports the default UTF-8 encoding name and numeric char codes for common
+ * ASCII characters used by path and parsing utilities.
  */
 
 // Encoding.

src/constants/github.ts

@@ -1,5 +1,7 @@
 /**
- * GitHub APIs and cache configuration.
+ * @fileoverview GitHub API and cache constants.
+ * Provides the GitHub REST API base URL and the cache subdirectory name used
+ * for persisting GitHub responses.
  */
 
 // GitHub API.

src/constants/licenses.ts

@@ -1,5 +1,7 @@
 /**
- * License identifiers and copy-left license sets.
+ * @fileoverview License identifier constants.
+ * Exports common SPDX license strings (MIT, UNLICENSED) and a lazily-built
+ * set of copy-left SPDX identifiers used when classifying package licenses.
  */
 
 // License identifiers.

src/constants/node.ts

@@ -1,5 +1,8 @@
 /**
- * Node.js runtime: versions, features, flags, and capabilities.
+ * @fileoverview Node.js runtime version and capability helpers.
+ * Provides getters for the current Node version (major/minor/patch), the
+ * maintained-versions list, and feature-detection flags for APIs that vary
+ * across Node releases.
  */
 
 import process from 'node:process'

src/constants/packages.ts

@@ -1,5 +1,8 @@
 /**
- * Package metadata, defaults, extensions, and lifecycle scripts.
+ * @fileoverview Package metadata, defaults, extensions, and lifecycle helpers.
+ * Exposes lazily-memoized accessors for package defaults (Node range, Socket
+ * categories), the pacote cache path, lifecycle script names, and known
+ * package extensions used during manifest processing.
  */
 
 import { getNpmLifecycleEvent as getNpmLifecycleEventEnv } from '../env/npm'

src/constants/process.ts

@@ -1,5 +1,7 @@
 /**
- * Process control: abort signals and UI utilities.
+ * @fileoverview Process control helpers.
+ * Lazily creates and exposes a shared `AbortController` and its `AbortSignal`
+ * so cooperating modules can coordinate cancellation from a single source.
  */
 
 // Abort controller and signal.