fix: update QuickStart guide and SSL config for local Postgres dev

The default database URL used sslmode=require, but the docker-compose
Postgres has no SSL configured — causing mantle init to fail for users
following the QuickStart guide. Change the code default to sslmode=disable
(matching the docs and the localhost dev URL) and add SSL guidance to
the Getting Started guide. Production examples throughout the docs
already use sslmode=require.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: michaelmcnees

docs/getting-started.md

@@ -34,6 +34,14 @@ make build
 
 The `docker compose up -d` command starts Postgres 16 on `localhost:5432` with user `mantle`, password `mantle`, and database `mantle`. The `make build` command produces a single `mantle` binary in the project root. The `mantle init` command creates all required database tables.
 
+The default database URL uses `sslmode=disable`, which is correct for local development with the provided Docker Compose setup. For production, always use `sslmode=require` or `sslmode=verify-full`:
+
+```bash
+export MANTLE_DATABASE_URL="postgres://mantle:secret@db.example.com:5432/mantle?sslmode=require"
+```
+
+See [Configuration](configuration.md) for all database options.
+
 You should see:
 
 ```

internal/config/config.go

@@ -129,7 +129,7 @@ func Load(cmd *cobra.Command) (*Config, error) {
 	v := viper.New()
 
 	// Defaults
-	v.SetDefault("database.url", "postgres://mantle:mantle@localhost:5432/mantle?sslmode=require")
+	v.SetDefault("database.url", "postgres://mantle:mantle@localhost:5432/mantle?sslmode=disable")
 	v.SetDefault("database.max_open_conns", 25)
 	v.SetDefault("database.max_idle_conns", 25)
 	v.SetDefault("database.conn_max_lifetime", 5*time.Minute)

internal/config/config_test.go

@@ -29,7 +29,7 @@ func TestLoad_Defaults(t *testing.T) {
 		t.Fatalf("Load() error = %v", err)
 	}
 
-	if cfg.Database.URL != "postgres://mantle:mantle@localhost:5432/mantle?sslmode=require" {
+	if cfg.Database.URL != "postgres://mantle:mantle@localhost:5432/mantle?sslmode=disable" {
 		t.Errorf("Database.URL = %q, want default", cfg.Database.URL)
 	}
 	if cfg.API.Address != ":8080" {
@@ -97,7 +97,7 @@ func TestLoad_ImplicitConfigMissing_UsesDefaults(t *testing.T) {
 		t.Fatalf("Load() error = %v, want nil (silent fallback)", err)
 	}
 
-	if cfg.Database.URL != "postgres://mantle:mantle@localhost:5432/mantle?sslmode=require" {
+	if cfg.Database.URL != "postgres://mantle:mantle@localhost:5432/mantle?sslmode=disable" {
 		t.Errorf("Database.URL = %q, want default", cfg.Database.URL)
 	}
 }

site/src/content/docs/getting-started/index.md

@@ -34,6 +34,14 @@ make build
 
 The `docker compose up -d` command starts Postgres 16 on `localhost:5432` with user `mantle`, password `mantle`, and database `mantle`. The `make build` command produces a single `mantle` binary in the project root. The `mantle init` command creates all required database tables.
 
+The default database URL uses `sslmode=disable`, which is correct for local development with the provided Docker Compose setup. For production, always use `sslmode=require` or `sslmode=verify-full`:
+
+```bash
+export MANTLE_DATABASE_URL="postgres://mantle:secret@db.example.com:5432/mantle?sslmode=require"
+```
+
+See [Configuration](/configuration) for all database options.
+
 You should see:
 
 ```