professionalize repo for public release

- rename ctcloud -> bucketeer everywhere (cmd/bucketeer, binary, compose service)
- group brand assets under assets/ (light/dark logo + UI screenshot)
- move long-form docs under docs/ (ARCHITECTURE, DESIGN, GOAL) and add
  docs/SKILL.md: how an agent queries/audits a running instance and answers
  user questions from the API and PostgreSQL
- README: large logo (light/dark picture) and UI screenshot, repository layout
- .gitignore: /bucketeer, .env, pgdata, build/test artifacts, OS junk
- .dockerignore: keep brand/docs/markdown out of the build context

internal/config/config.go

@@ -1,4 +1,4 @@
-// Package config loads all ctcloud configuration from environment variables.
+// Package config loads all bucketeer configuration from environment variables.
 // There are no configuration files at runtime.
 package config
 

internal/config/config_test.go

@@ -6,12 +6,12 @@ import (
 )
 
 func TestLoadDefaults(t *testing.T) {
-	t.Setenv("DATABASE_URL", "postgres://localhost/ctcloud")
+	t.Setenv("DATABASE_URL", "postgres://localhost/bucketeer")
 	c, err := Load()
 	if err != nil {
 		t.Fatal(err)
 	}
-	if c.DatabaseURL != "postgres://localhost/ctcloud" {
+	if c.DatabaseURL != "postgres://localhost/bucketeer" {
 		t.Fatalf("database url = %q", c.DatabaseURL)
 	}
 	if c.DNSWorkers != 64 || c.DNSMaxCNAMEdepth != 8 {
@@ -23,7 +23,7 @@ func TestLoadDefaults(t *testing.T) {
 }
 
 func TestLoadOverrides(t *testing.T) {
-	t.Setenv("DATABASE_URL", "postgres://localhost/ctcloud")
+	t.Setenv("DATABASE_URL", "postgres://localhost/bucketeer")
 	t.Setenv("DNS_WORKERS", "4")
 	t.Setenv("ACTIVE_PROBING", "true")
 	t.Setenv("DB_FLUSH_INTERVAL", "250ms")
@@ -45,7 +45,7 @@ func TestLoadInvalid(t *testing.T) {
 	if _, err := Load(); err == nil {
 		t.Fatal("expected error without DATABASE_URL")
 	}
-	t.Setenv("DATABASE_URL", "postgres://localhost/ctcloud")
+	t.Setenv("DATABASE_URL", "postgres://localhost/bucketeer")
 	t.Setenv("LOG_LEVEL", "verbose")
 	if _, err := Load(); err == nil {
 		t.Fatal("expected error for bad LOG_LEVEL")