ci(examples): assert exact status/body instead of liveness-only check (#755)

* ci(examples): assert exact status/body instead of liveness-only check

The verify step in test-image/test-zip/test-stream treated any 2xx-4xx
response as success, so a broken route (404) or an app that booted but
served the wrong/empty content still passed.

Add .github/scripts/verify-http.sh which waits for an endpoint to return
an exact status code and (optionally) a known body substring, and convert
each job's matrix to objects carrying {path, expect_status, expect_body}
so every example asserts its real response.

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

* fix(examples): honor PORT in fasthtml-response-streaming

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: JamBalaya56562

.github/scripts/verify-http.sh

@@ -0,0 +1,65 @@
+#!/usr/bin/env bash
+#
+# Verify that an example's HTTP endpoint serves the expected response.
+#
+# Unlike a plain liveness check (any 2xx-4xx == "OK"), this asserts that a
+# specific route returns an exact status code and, optionally, that the body
+# contains a known substring. This catches broken routing and apps that boot
+# but serve the wrong (or empty) content.
+#
+# Usage:
+#   verify-http.sh <base_url> <path> <expect_status> [expect_body]
+#
+#   base_url      e.g. http://127.0.0.1:3000
+#   path          request path, e.g. / or /healthz
+#   expect_status comma-separated acceptable status codes, e.g. "200" or "200,307"
+#   expect_body   optional substring that must appear in the response body
+#
+# Waits up to 90s (wall-clock) for the endpoint to satisfy BOTH conditions
+# (the app may still be warming up), then exits 0 on success or 1 with
+# diagnostics. Uses a wall-clock deadline plus a short per-request timeout
+# (curl -m 5) so a hanging endpoint can't multiply the wait window.
+
+set -uo pipefail
+
+BASE_URL="${1:?base_url required}"
+REQ_PATH="${2:-/}"
+EXPECT_STATUS="${3:-200}"
+EXPECT_BODY="${4:-}"
+
+URL="${BASE_URL%/}${REQ_PATH}"
+IFS=',' read -ra ACCEPT <<< "$EXPECT_STATUS"
+
+status_ok() {
+  local s="$1"
+  for code in "${ACCEPT[@]}"; do
+    [ "$s" = "$code" ] && return 0
+  done
+  return 1
+}
+
+echo "Verifying ${URL} (expect status ${EXPECT_STATUS}${EXPECT_BODY:+, body contains \"${EXPECT_BODY}\"})"
+
+last_status=""
+last_body=""
+START=$SECONDS
+DEADLINE=$((START + 90))
+while [ $SECONDS -lt $DEADLINE ]; do
+  resp="$(curl -s -m 5 -w $'\n%{http_code}' "$URL" 2>/dev/null || true)"
+  last_status="${resp##*$'\n'}"
+  last_body="${resp%$'\n'*}"
+  if status_ok "$last_status"; then
+    if [ -z "$EXPECT_BODY" ] || grep -qF -- "$EXPECT_BODY" <<< "$last_body"; then
+      echo "OK after $((SECONDS - START))s: status ${last_status}${EXPECT_BODY:+, body contains \"${EXPECT_BODY}\"}"
+      exit 0
+    fi
+  fi
+  sleep 1
+done
+
+echo "FAIL: expectation not met within 90s (elapsed $((SECONDS - START))s)"
+echo "  last status: ${last_status:-<none>} (expected ${EXPECT_STATUS})"
+[ -n "$EXPECT_BODY" ] && echo "  expected body substring: ${EXPECT_BODY}"
+echo "--- last response body (first 30 lines) ---"
+printf '%s\n' "$last_body" | head -30
+exit 1