Fix/test docs and header manipulation arrays

context/CONTEXT_INDEX.md

@@ -12,7 +12,7 @@ This index helps you discover relevant documentation without reading thousands o
 **Purpose**: Postman-like test runner for debugging proxy-wasm binaries locally
 **Tech Stack**: Node.js + Express + TypeScript (backend) | React + Vite + TypeScript + Zustand (frontend)
 **WASM Runtime**: Node WebAssembly API with WASI preview1
-**Port**: 5179 (auto-increments through 5179-5188 if busy)
+**Port**: 5179 (auto-increments through 5179-5228 if busy)
 
 **Current Branch**: See git status
 **Philosophy**: Production parity, no over-engineering, type safety, modular architecture
@@ -44,7 +44,7 @@ This index helps you discover relevant documentation without reading thousands o
 - `FASTEDGE_IMPLEMENTATION.md` (645 lines) - FastEdge CDN integration, secrets, env vars
 - `PROPERTY_IMPLEMENTATION_COMPLETE.md` (495 lines) - Property system, runtime calculation
 - `PRODUCTION_PARITY_HEADERS.md` (421 lines) - Header serialization, G-Core SDK format
-- `MULTI_VALUE_HEADERS.md` (~200 lines) - Multi-value header support, internal tuple storage, nginx remove behavior, cdn-headers integration test (AS + Rust)
+- `MULTI_VALUE_HEADERS.md` (~230 lines) - Multi-value header support: three type layers (HeaderMap/HeaderTuples/HeaderRecord), lossless tuplesToRecord projection, Set-Cookie / RFC 6265 §3 correctness end-to-end, AS validation app ported in-repo (Apr 2026), cdn-headers + http-responder integration tests across all variants
 - `CONFIG_SHARING.md` (281 lines) - fastedge-config.test.json sharing system
 - `DOTENV.md` (~210 lines) - Environment variable system, dotenvPath support (CDN + HTTP)
 - `CDN_VARIABLES_AND_SECRETS.md` (~120 lines) - ✅ CDN env var/secret integration test (7 tests); requires proxy-wasm-sdk-as@^1.2.2
@@ -209,7 +209,7 @@ Applies when: tests fail because HTTP apps are run as proxy-wasm (or vice versa)
 
 **Architecture (April 2026)**: `dist/server.js` unconditionally calls `startServer()` on load. This works for both the CLI (`bin/fastedge-debug.js` does `import("../dist/server.js")`) and VSCode extension (`fork()`). Library consumers use `dist/lib/` entry points which do not auto-start.
 
-1. `startServer()` probes ports 5179-5188 via HTTP `/health` check; first available port wins
+1. `startServer()` probes ports 5179-5228 via HTTP `/health` check (50 slots, expanded from 10 in April 2026 for Codespaces / multi-session workflows); first available port wins
 2. Port file written to `{WORKSPACE_PATH || cwd()}/.fastedge-debug/.debug-port` (WORKSPACE_PATH defaults to `process.cwd()` so CLI users get port files too)
 3. Startup messages go to stderr (`console.error()`) so MCP stdio transport is not corrupted
 4. **Old pattern removed**: `require.main === module` guard was deleted because it fails in bundled CJS loaded via dynamic `import()`
@@ -386,4 +386,4 @@ Time: 5-7 minutes of reading
 
 ---
 
-**Last Updated**: April 13, 2026
+**Last Updated**: April 22, 2026

context/VSCODE_BUNDLING.md

@@ -168,7 +168,7 @@ npm run package
 - **VSCode extension**: `fork(serverPath)` — the forked module starts automatically
 - **Library consumers**: Use `dist/lib/` entry points (runner, test framework), which do NOT auto-start
 
-`startServer()` probes ports 5179-5188 via HTTP `/health` check before binding (port auto-increment moved from the VSCode extension's `DebuggerServerManager.resolvePort()` into the server). Port file written to `{WORKSPACE_PATH}/.fastedge-debug/.debug-port`. Both the CLI and VSCode extension resolve `WORKSPACE_PATH` before starting the server using the same priority: existing `.fastedge-debug/` dir > nearest `package.json`/`Cargo.toml` > cwd. Startup messages go to stderr so MCP stdio transport is not corrupted.
+`startServer()` probes ports 5179-5228 via HTTP `/health` check before binding (50 slots, expanded from 10 on 2026-04-22; port auto-increment moved from the VSCode extension's `DebuggerServerManager.resolvePort()` into the server). Port file written to `{WORKSPACE_PATH}/.fastedge-debug/.debug-port`. Both the CLI and VSCode extension resolve `WORKSPACE_PATH` before starting the server using the same priority: existing `.fastedge-debug/` dir > nearest `package.json`/`Cargo.toml` > cwd. Startup messages go to stderr so MCP stdio transport is not corrupted.
 
 ### Extension Runtime
 

context/architecture/BACKEND_ARCHITECTURE.md

@@ -745,20 +745,26 @@ When `dotenvEnabled=false`:
 
 ### types.ts
 
+Three header types coexist at different boundaries. See `context/features/MULTI_VALUE_HEADERS.md` for the full architecture.
+
+- **`HeaderMap = Record<string, string>`** — simple input shape (single value per key). Used by `FlowOptions.requestHeaders`, `HttpRequest.headers`, and similar user-supplied maps.
+- **`HeaderTuples = [string, string][]`** — canonical internal representation, lossless / ordered / duplicate-preserving. Used by `HostFunctions` as the WASM-visible header maps and by `HeaderManager.serializeTuples` for proxy-wasm binary format.
+- **`HeaderRecord = Record<string, string | string[]>`** — wire / hook-result format. Single-valued keys as `string`, multi-valued (notably `Set-Cookie` per RFC 6265 §3) as `string[]`. Matches Node's `IncomingHttpHeaders` projection.
+
 **HookCall:**
 
 ```typescript
 export type HookCall = {
   hook: string;
   request: {
-    headers: HeaderMap;
+    headers: HeaderRecord;    // wire format; accepts HeaderMap (subset) for convenience
     body: string;
     method?: string;
     path?: string;
     scheme?: string;
   };
   response: {
-    headers: HeaderMap;
+    headers: HeaderRecord;
     body: string;
     status?: number;
     statusText?: string;
@@ -775,13 +781,13 @@ export type HookResult = {
   returnCode: number | null;
   logs: { level: number; message: string }[];
   input: {
-    request: { headers: HeaderMap; body: string };
-    response: { headers: HeaderMap; body: string };
+    request: { headers: HeaderRecord; body: string };
+    response: { headers: HeaderRecord; body: string };
     properties?: Record<string, unknown>; // State before hook execution
   };
   output: {
-    request: { headers: HeaderMap; body: string };
-    response: { headers: HeaderMap; body: string };
+    request: { headers: HeaderRecord; body: string };
+    response: { headers: HeaderRecord; body: string };
     properties?: Record<string, unknown>; // State after hook execution
   };
   properties: Record<string, unknown>; // Final merged properties
@@ -796,7 +802,7 @@ export type FullFlowResult = {
   finalResponse: {
     status: number;
     statusText: string;
-    headers: HeaderMap;
+    headers: HeaderRecord;
     body: string;
     contentType: string;
     isBase64?: boolean;
@@ -805,6 +811,22 @@ export type FullFlowResult = {
 };
 ```
 
+**HttpResponse (HTTP-WASM public output):**
+
+```typescript
+import type { IncomingHttpHeaders } from "node:http";
+
+export interface HttpResponse {
+  status: number;
+  statusText: string;
+  headers: IncomingHttpHeaders;  // set-cookie: string[]; common headers narrowed to string
+  body: string;
+  contentType: string | null;
+  isBase64?: boolean;
+  logs: Array<{ level: number; message: string }>;
+}
+```
+
 **Calculated Properties (February 2026):**
 
 The `calculatedProperties` field contains runtime-extracted properties from the target URL:

context/features/CROSS_PLATFORM.md

@@ -96,7 +96,7 @@ The `exit` event fires for normal exits and unhandled exceptions on all platform
 
 **WORKSPACE_PATH default (April 2026)**: `getPortFilePath()` defaults `WORKSPACE_PATH` to `process.cwd()`, so CLI users get port files and config resolution too (previously only set by the VSCode extension).
 
-**Port auto-increment (April 2026)**: `startServer()` probes ports 5179-5188 via HTTP `/health` check before binding. If a port is busy, tries the next one. This logic was moved from the VSCode extension's `DebuggerServerManager.resolvePort()` into the server itself.
+**Port auto-increment (April 2026)**: `startServer()` probes ports 5179-5228 via HTTP `/health` check before binding (50 slots, expanded from 10 on 2026-04-22 for Codespaces / multi-session workflows). If a port is busy, tries the next one. This logic was moved from the VSCode extension's `DebuggerServerManager.resolvePort()` into the server itself.
 
 ---