Move the example config to configs/, delete scripts/ and CONVENTIONS.md (closes #97)

config.example.yml moves unchanged to configs/config.example.yml, the
directory REPO_POLICIES.md names for configuration examples. README.md,
the comments in internal/config/config.go and the startup error for the
placeholder signing key name the new path. scripts/manual-test.sh and
its directory are deleted: each check it made against a running server
is now a handler test in internal/handlers. CONVENTIONS.md, a reformatted
copy of the Go HTTP server conventions, is deleted, as REPO_POLICIES.md
links the canonical document.

Model: opus-5-5

TODO.md

@@ -36,19 +36,9 @@ P2: security: referer blacklist
   `README.md`, the comments in `internal/config/config.go` and the startup error
   for the placeholder signing key name the new path; `scripts/manual-test.sh`
   and its directory are deleted, as the handler tests in `internal/handlers`
-  cover every check it made except two: fetching a real image from the
-  internet, and a URL made on the generator page with a `ttl` answering 410 once
-  the `ttl` has passed (https://git.eeqj.de/sneak/pixa/issues/199);
+  cover every check it made except fetching a real image from the internet;
   `CONVENTIONS.md` is deleted, as `REPO_POLICIES.md` links the canonical Go HTTP
   server conventions.
-- 2026-10-04 `TestPeriodicReconciliationAdoptsFileThatAppearsAfterStartup`
-  only passes through a periodic pass (closes #189): it slept for three
-  eviction intervals before writing its file, and a startup pass still running
-  then could adopt the file itself. It now holds the test database's only
-  connection until the startup pass waits for it after walking the empty
-  variant directory, writes the file and lets the connection go, as
-  `TestEvictionRunsOnPeriodicSchedule` does, so only a periodic reconciliation
-  pass can adopt the file. Test only.
 - 2026-10-04 logging in, logging out, the URL generator and `/v1/e/` have
   handler tests (closes #77): new tests in `internal/handlers`, with no
   network, check that `GET /` without a login session shows the login form; a

internal/imgcache/eviction_internal_test.go

@@ -847,28 +847,15 @@ func TestPeriodicReconciliationAdoptsFileThatAppearsAfterStartup(t *testing.T) {
 
 	cache, _ := newEvictionTestCache(t, 1<<30)
 
-	// Hold the test database's only connection, so the startup pass
-	// waits for it after walking the still empty variant directory: the
-	// file written while it waits is first seen by a periodic pass.
-	conn, err := cache.db.Conn(t.Context())
-	if err != nil {
-		t.Fatalf("failed to take the database connection: %v", err)
-	}
+	const interval = 100 * time.Millisecond
 
-	defer func() { _ = conn.Close() }()
-
-	cache.StartEviction(100 * time.Millisecond)
+	cache.StartEviction(interval)
 	defer func() { _ = cache.StopEviction(t.Context()) }()
 
-	deadline := time.Now().Add(5 * time.Second)
-
-	for cache.db.Stats().WaitCount == 0 {
-		if time.Now().After(deadline) {
-			t.Fatal("the startup pass never waited for the database")
-		}
-
-		time.Sleep(10 * time.Millisecond)
-	}
+	// Let startup reconciliation run and settle on an empty cache
+	// before introducing the untracked file, so the adoption we assert
+	// below can only be the work of a later, periodic pass.
+	time.Sleep(3 * interval)
 
 	// Simulate a variant whose accounting insert failed after the
 	// process was already running and serving requests: the content
@@ -877,16 +864,14 @@ func TestPeriodicReconciliationAdoptsFileThatAppearsAfterStartup(t *testing.T) {
 	// insert had failed and only the file write had succeeded.
 	untracked := bytes.Repeat([]byte{0x41}, 900)
 
-	_, err = cache.variants.Store(
+	_, err := cache.variants.Store(
 		"aabbccdd0099", bytes.NewReader(untracked), "image/webp",
 	)
 	if err != nil {
 		t.Fatalf("failed to store untracked variant file: %v", err)
 	}
 
-	_ = conn.Close()
-
-	deadline = time.Now().Add(5 * time.Second)
+	deadline := time.Now().Add(5 * time.Second)
 
 	var usage int64