docs: surface dual-loader support (envconfig + env-tag) on framework pages

FAQ.md

@@ -211,7 +211,7 @@ Yes — ColdBrew is Kubernetes-native by design. Out of the box you get:
 - **Graceful shutdown** on SIGTERM with configurable drain periods (`SHUTDOWN_DURATION_IN_SECONDS`, `GRPC_GRACEFUL_DURATION_IN_SECONDS`)
 - **Prometheus metrics** at `/metrics` for scraping
 - **Structured JSON logging** to stdout (ready for Fluentd, Loki, or any log aggregator)
-- **Environment variable configuration** via [envconfig](https://github.com/kelseyhightower/envconfig) — works natively with ConfigMaps and Secrets
+- **Environment variable configuration** via [envconfig](https://github.com/kelseyhightower/envconfig) or any `env:`-tag loader (e.g. [caarlos0/env](https://github.com/caarlos0/env)) — works natively with ConfigMaps and Secrets
 
 ColdBrew also follows [12-factor app](https://12factor.net/) principles: no config files, stateless processes, port binding, and log streams. See the [Production Deployment guide](/howto/production) for K8s manifests, ServiceMonitor setup, and graceful shutdown tuning, and the [Architecture](/architecture) page for the full design principles table.
 

Packages.md

@@ -20,7 +20,7 @@ The core module is the base module and provides the base implementation for Cold
 Documentation can be found at [core-docs]
 
 ### [Config]
-ColdBrew config package contains the configuration for the core package. It uses [envconfig] to load the configuration from the environment variables.
+ColdBrew config package contains the configuration for the core package. Each field carries both `envconfig:"…"` and `env:"…"` struct tags, so it can be loaded with [envconfig] (the cookiecutter default) or any `env:`-tag loader such as [caarlos0/env](https://github.com/caarlos0/env).
 
 Documentation can be found at [config-docs]
 

architecture.md

@@ -22,7 +22,7 @@ ColdBrew follows [12-factor app](https://12factor.net/) methodology and is desig
 
 | 12-Factor Principle | How ColdBrew Implements It |
 |--------------------|-----------------------------|
-| **Config** | All configuration via environment variables ([envconfig](https://github.com/kelseyhightower/envconfig)) — no config files, no YAML. See [Configuration Reference](/config-reference) |
+| **Config** | All configuration via environment variables — works with [envconfig](https://github.com/kelseyhightower/envconfig) or any `env:`-tag loader like [caarlos0/env](https://github.com/caarlos0/env). No config files, no YAML. See [Configuration Reference](/config-reference) |
 | **Port binding** | Self-contained HTTP (`:9091`) and gRPC (`:9090`) servers, optional dedicated admin port (`ADMIN_PORT`) for endpoint isolation |
 | **Logs** | Structured JSON to stdout by default — ready for any log aggregator (Fluentd, Loki, CloudWatch) |
 | **Disposability** | Graceful SIGTERM handling with configurable drain periods. See [Signals](/howto/signals) |

config-reference.md

@@ -16,7 +16,7 @@ permalink: /config-reference
 
 ---
 
-ColdBrew is configured entirely through environment variables using [envconfig](https://github.com/kelseyhightower/envconfig). All fields have sensible defaults — you can run a service with zero configuration.
+ColdBrew is configured entirely through environment variables. The framework `Config` struct carries both `envconfig:"…"` and `env:"…"` struct tags, so services can populate it with [kelseyhightower/envconfig](https://github.com/kelseyhightower/envconfig) (the cookiecutter default) or any `env:`-tag loader such as [caarlos0/env](https://github.com/caarlos0/env), [sethvargo/go-envconfig](https://github.com/sethvargo/go-envconfig), or [ilyakaznacheev/cleanenv](https://github.com/ilyakaznacheev/cleanenv). All fields have sensible defaults — you can run a service with zero configuration.
 
 Access the config in code via:
 

howto/APIs.md

@@ -765,7 +765,6 @@ Benchmark source: [`benchmarks/`](https://github.com/go-coldbrew/core/tree/main/
 [google/rpc/code.proto]: https://github.com/googleapis/googleapis/blob/master/google/rpc/code.proto
 [ColdBrew errors package]: https://pkg.go.dev/github.com/go-coldbrew/errors#NewWithStatus
 [errors package]: https://pkg.go.dev/github.com/go-coldbrew/errors
-[envconfig]: https://github.com/kelseyhightower/envconfig
 [ColdBrew]: https://docs.coldbrew.cloud
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