🔧 e2e mock: address review — clarify backend flag, move ignore to root

- Document the --backend-addr flag: it is the stub upstream service Traefik
  proxies allowed requests to (the traefik/whoami equivalent), not AppSec.
- Move the .cache/ ignore rule from the per-suite .gitignore to the repo root
  .gitignore, and make the wording accurate: the cache persists across local
  runs but is recreated on every (fresh-runner) CI run.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.gitignore

@@ -5,3 +5,7 @@ conf
 db
 logs
 docker-compose.dev.yml
+
+# Binary e2e suite working cache: Traefik binary + compiled mock. Persisted
+# across local runs; CI runs on fresh runners so it is recreated every time.
+tests/e2e/mock/.cache/

tests/e2e/mock/.gitignore

@@ -1,2 +0,0 @@
-# Cached Traefik binary and compiled mock, produced on first run.
-.cache/

tests/e2e/mock/README.md

@@ -28,7 +28,7 @@ returns whatever decisions the test tells it to.
 
 | Component | How |
 |-----------|-----|
-| Traefik   | Binary `v3.7.1`, downloaded once and cached under `.cache/` |
+| Traefik   | Binary `v3.7.1`, downloaded into `.cache/` (reused across local runs; re-downloaded on fresh CI runners) |
 | Plugin    | Loaded via `experimental.localPlugins` from the repo root (symlinked into `plugins-local/`) |
 | LAPI      | `mocklapi` — a stdlib-only Go command (its own nested module), compiled and cached under `.cache/`, driven through `/admin` endpoints instead of `cscli` |
 | Backend   | A plain HTTP responder built into the mock |
@@ -38,8 +38,9 @@ backend `8091`.
 
 ## Running locally
 
-Prerequisites: `bash`, `curl`, `go`, `tar`. The Traefik binary is fetched and
+Prerequisites: `bash`, `curl`, `go`, `tar`. On first use the Traefik binary is
-the mock is compiled automatically on first run (both cached under `.cache/`).
+fetched and the mock is compiled into `.cache/`. That cache is reused across
+local runs; CI runs on fresh runners, so both are recreated on every CI run.
 
 ```bash
 # one scenario

tests/e2e/mock/lib/common.sh

@@ -7,7 +7,8 @@
 # IPs, ban / captcha rendering), NOT Crowdsec or AppSec correctness.
 #
 # Dependencies: bash, curl, go, tar. The Traefik binary is downloaded and the
-# mock is compiled on first run (both cached), so local and CI behave the same.
+# mock is compiled into .cache/ on first use. That cache persists across local
+# runs; CI runs on fresh runners, so both are recreated on every CI run.
 
 set -euo pipefail
 

tests/e2e/mock/mocklapi/main.go

@@ -213,7 +213,9 @@ func backendHandler() http.Handler {
 
 func main() {
 	lapiAddr := flag.String("lapi-addr", "127.0.0.1:8090", "address for the LAPI mock")
-	backendAddr := flag.String("backend-addr", "127.0.0.1:8091", "address for the backend responder")
+	// The stub upstream service Traefik proxies allowed requests to — the
+	// binary-suite equivalent of the traefik/whoami container. Not AppSec.
+	backendAddr := flag.String("backend-addr", "127.0.0.1:8091", "address of the stub upstream service Traefik proxies allowed requests to")
 	apiKey := flag.String("api-key", "e2e-mock-key", "expected X-Api-Key value")
 	flag.Parse()