docs: update testing docs and justfile for reorganized test commands

Restructure justfile test commands: test → all fast tests (Rust+TS),
test-rust → Rust only, test-nix → nix flake check (absorbs test-full,
check-nix), remove test-all (redundant). Update all 6 docs to match.

Author: dezren39

doc/2026-03-29T00-00-00Z_reference_testing_architecture/2026-03-29T00-00-00Z_reference_testing_architecture.md

@@ -106,9 +106,14 @@ just ci         # CI-safe read-only checks (no modifications)
 just fix        # Auto-fix formatting and lint issues
 just serve      # Serve with web UI [requires bun]
 just run        # Run CLI with arguments
+just test       # All fast tests (Rust + TypeScript unit + typecheck)
 just test-unit  # Unit tests only (fast)
+just test-e2e   # Playwright E2E (146 tests, chromium + firefox)
+just test-nix   # nix flake check (26 checks including VM Playwright)
 ```
 
+**Testing architecture:** See [`doc/testing-architecture`](../../doc/2026-03-29T00-00-00Z_reference_testing_architecture/2026-03-29T00-00-00Z_reference_testing_architecture.md) for the complete 6-layer testing reference, browser coverage matrix, environment comparison, and "when to add tests where" decision tree.
+
 Ask user before updating dependencies.
 
 ## CLI Commands

pkgs/id/AGENTS.md

@@ -225,11 +225,14 @@ The build script (`scripts/build.sh`) tracks the current variant in `target/.bui
 
 ## Testing
 
-| Layer       | Framework    | Command              | Count |
-| ----------- | ------------ | -------------------- | ----- |
-| Unit        | `cargo test` | `just test-unit`     | 484   |
-| Integration | `cargo test` | `just test-int`      | 64    |
-| TypeScript  | `bun test`   | `just test-web-unit` | —     |
-| E2E         | Playwright   | `just test-e2e`      | 15    |
-
-Integration tests that require network (serve_tests) are skipped in sandbox environments. Playwright E2E tests run against both Chromium and Firefox.
+| Layer          | Framework    | Command              | Count  |
+| -------------- | ------------ | -------------------- | ------ |
+| Unit           | `cargo test` | `just test-unit`     | ~500   |
+| Integration    | `cargo test` | `just test-int`      | ~85    |
+| TypeScript     | `bun test`   | `just test-web-unit` | ~116   |
+| E2E            | Playwright   | `just test-e2e`      | 146    |
+| NixOS VM (API) | curl/Python  | `just test-nixos-serve` | ~15 |
+| NixOS VM (DOM) | Chromium     | `just test-nixos-e2e`   | ~10 |
+| NixOS 4-VM (Playwright) | Playwright | `nix build .#checks.x86_64-linux.nixos-playwright-e2e` | 146 |
+
+Integration tests that require network (`serve_tests`) are skipped in sandbox environments. Playwright E2E tests run against both Chromium and Firefox. The 4-VM Playwright test runs the full interactive suite inside NixOS VMs where Chromium works (unlike the nix build sandbox). See [`doc/testing-architecture`](../../doc/2026-03-29T00-00-00Z_reference_testing_architecture/2026-03-29T00-00-00Z_reference_testing_architecture.md) for the complete testing reference.

pkgs/id/ARCHITECTURE.md

@@ -183,22 +183,26 @@ This provides: Rust 1.89.0, clippy, rustfmt, cargo-llvm-cov, cargo-audit, cargo-
 ### Testing
 
 ```bash
-just test-unit         # Unit tests (fast)
-just test-int          # Integration tests
-just test              # All Rust tests
-just test-web-unit     # TypeScript unit tests
-just test-web          # All web tests
-just test-e2e          # Playwright E2E (chromium + firefox)
+just test              # All fast tests (Rust + TypeScript unit + typecheck)
+just test-rust         # Rust tests only (~500 unit + ~85 integration)
+just test-unit         # Unit tests only (fast, ~500 tests)
+just test-integration  # Integration tests only (~85 tests)
+just test-web-unit     # TypeScript unit tests (~116 assertions)
+just test-e2e          # Playwright E2E (chromium + firefox, 146 tests)
+just test-nix          # nix flake check (26 checks including VM Playwright)
 just ci                # Full CI check suite
 just check             # Fix + CI (run before committing)
 ```
 
+See [`doc/testing-architecture`](../../doc/2026-03-29T00-00-00Z_reference_testing_architecture/2026-03-29T00-00-00Z_reference_testing_architecture.md) for the complete testing reference: 6 test layers, browser coverage matrix, environment comparison, and when to add tests where.
+
 ### Nix
 
 ```bash
 nix build              # Build web variant
 nix build .#id-lib     # Build lib variant
-nix flake check -L     # Run all CI checks in sandbox
+just test-nix          # Run all 26 CI checks in sandbox (aliases: test-full, check-nix)
+nix build .#checks.x86_64-linux.nixos-playwright-e2e  # Full Playwright in 4 NixOS VMs
 ```
 
 ## Project Structure
@@ -238,12 +242,18 @@ web/                     # TypeScript frontend
 ├── styles/              # Terminal CSS, themes, editor styles
 └── dist/                # Built assets (embedded in binary)
 
-e2e/                     # Playwright E2E tests
-├── tests/basic.spec.ts  # 15 tests across chromium + firefox
-└── playwright.config.ts # Browser config with nix paths
+e2e/                     # Playwright E2E tests (38 tests × 2 browsers = 146)
+├── tests/basic.spec.ts      # 19 UI fundamental tests
+├── tests/websocket.spec.ts  # 19 WS + collaboration tests
+└── playwright.config.ts     # 3-mode config: local / nix sandbox / VM test
+
+nix/tests/                   # NixOS VM integration tests
+├── serve-test.nix           # HTTP API test (curl, ~15 assertions)
+├── e2e-test.nix             # Chromium --dump-dom DOM test (~10 assertions)
+└── playwright-e2e-test.nix  # 4-VM full Playwright (146 interactive tests)
 
 tests/
-└── cli_integration.rs   # 64 integration tests
+└── cli_integration.rs   # ~85 integration tests
 ```
 
 ## Documentation

pkgs/id/README.md

@@ -104,9 +104,10 @@ src/web/
 └── markdown.rs           # Markdown rendering with syntax highlighting
 
 e2e/
-├── playwright.config.ts  # Chromium + Firefox config
+├── playwright.config.ts  # 3-mode config: local / nix sandbox / VM test
 └── tests/
-    └── basic.spec.ts     # 15 E2E tests
+    ├── basic.spec.ts     # 19 UI fundamental tests
+    └── websocket.spec.ts # 19 WS + collaboration tests
 ```
 
 ### Justfile Commands
@@ -261,15 +262,15 @@ just test-unit
 
 ### E2E Tests
 
-Playwright tests run against both Chromium and Firefox:
+Playwright tests run against both Chromium and Firefox (38 tests × 2 browsers = 146 total):
 
 ```bash
-just test-e2e          # Both browsers
-just test-e2e-chromium # Chromium only
-just test-e2e-firefox  # Firefox only
+just test-e2e          # Both browsers (146 tests)
+just test-e2e-chromium # Chromium only (73 tests)
+just test-e2e-firefox  # Firefox only (73 tests)
 ```
 
-Tests cover: home page elements, file creation, editor features, navigation, themes.
+Tests cover: home page elements, file creation, editor features, navigation, themes, WebSocket connection/disconnect/reconnect, collaborative editing, multi-user scenarios, tag live updates.
 
 Browser paths are configured via environment variables for nix compatibility:
 

pkgs/id/WEB.md

@@ -208,8 +208,14 @@ just-recipes:
 
 # Run all Rust tests
 [group('test')]
-test:
+test-rust:
     cargo test --all-features
+alias test-cargo := test-rust
+
+# Run all fast tests (Rust + TypeScript unit + typecheck)
+[group('test')]
+test: test-rust test-web-unit test-web-typecheck
+    @echo "✓ All fast tests passed (Rust + TypeScript)!"
 
 # Run all Rust tests (sandbox-safe: excludes tests requiring network)
 [group('test')]
@@ -224,8 +230,9 @@ alias test-lib := test-unit
 
 # Run integration tests only
 [group('test')]
-test-int:
+test-integration:
     cargo test --all-features --test cli_integration
+alias test-int := test-integration
 
 # Run integration tests (sandbox-safe: excludes serve_tests requiring network)
 [group('test')]
@@ -244,7 +251,7 @@ test-one NAME:
 
 # [bun] Run web tests (Rust + TypeScript unit tests + type checking)
 [group('test')]
-test-web: test test-web-unit test-web-typecheck
+test-web: test-rust test-web-unit test-web-typecheck
     @echo "✓ All web tests passed!"
 alias web-typecheck := test-web
 
@@ -263,18 +270,14 @@ test-web-unit:
 test-web-typecheck:
     cd web && bun run typecheck
 
-# Run ALL tests including serve_tests and E2E (requires network + built binary) [bun]
-[group('test')]
-test-all: test test-web-unit test-web-typecheck test-e2e
-    @echo "✓ All tests passed (including serve_tests + E2E)!"
-
-# Run every test: nix flake check (25 sandboxed checks) + E2E with both browsers outside sandbox
+# Run nix flake check (26 sandboxed checks: lint, test, E2E, NixOS VM tests, VM Playwright)
 [group('test')]
-test-full:
+test-nix:
     nix flake check
-    @echo "✓ nix flake check passed (25 checks including Firefox E2E + NixOS VM tests)"
-    just test-e2e
-    @echo "✓ All tests passed (nix flake check + Chromium & Firefox E2E)!"
+    @echo "✓ nix flake check passed (26 checks including VM Playwright + NixOS VM tests)"
+alias test-full := test-nix
+alias check-nix := test-nix
+alias nix-check := test-nix
 
 # =============================================================================
 # E2E Tests (Playwright - requires built web variant + network)
@@ -648,14 +651,9 @@ update-nixpkgs-unstable-only:
     just update-input $inputs
 
 # =============================================================================
-# Nix
+# Nix (individual VM tests — prefer test-nix for full suite)
 # =============================================================================
 
-# Run nix flake check (full sandboxed CI, only x86_64-linux)
-[group('nix')]
-check-nix:
-    nix flake check
-
 # Run NixOS VM serve integration test (requires KVM, Linux only)
 [group('nix')]
 test-nixos-serve: