# 1.0.0 — Extracted into a package of its own

The first release of `@bayudwiyansatria/core`. The kernel that lived inside an application as `src/core/system/` is now
a package, so every service that wants this architecture shares one copy rather than forking it.

The extraction was anticipated. That directory's own module documentation said it was _"meant to be liftable into a
package the other services can share"_, and an ESLint boundary rule had been enforcing the constraint. It held: across
all 45 files, the only import pointing outward was the one documented exception.

This repository previously held the Node.js library template. Its scaffolding was replaced with the newer generation —
flat ESLint config, four Rollup outputs with an `exports` map, the TypeDoc gate — and its placeholder source removed.

## What this package provides

| Category      | Exports                                                                                     |
| ------------- | ------------------------------------------------------------------------------------------- |
| Contracts     | `Service`, `APIResponse`                                                                    |
| Capabilities  | `Capability`, the ten interfaces over it, `RequestMetadata`, their shapes, the `Noop*` four |
| Configuration | `configure`, `resolve`, `systemDefaults`, the settings shapes                               |
| Observability | `Logger`, `LogContext`                                                                      |
| Security      | `timingSafeEqual`                                                                           |
| Errors        | `MissingCapabilityError`, `ConfigurationError`                                              |
| Utilities     | `Signature`, `Text`, `Time`                                                                 |

42 names in all, from a single entry point. The `exports` map exposes `.` and `./package.json` and nothing else, so
there are no deep import paths to depend on — `src/` may be rearranged in a patch release without it being a breaking
change.

## What changed in the move

### `configure()` replaces the import of `src/config/`

`resolve()` used to import the application's configuration directly. That is fine inside one repository and impossible
across a package boundary — a package cannot reach into its consumer's source tree.

The application now assembles the surface and hands it over:

```ts
configure({ ...systemDefaults, ...platformDefaults }, overrides)
```

The merge semantics carry over exactly: per field rather than per module, and an override set explicitly to `undefined`
is ignored.

### `ConfigurationError` is new

`resolve()` throws it for a module registered nowhere, and the message names both ways that happens: `configure()` has
not run yet, or two copies of this package are loaded. The second is the nastier one — the registry is module state, so
a duplicate copy means one registry gets seeded and another gets read — and nothing about the stack trace would
otherwise suggest a packaging problem.

Returning `undefined` instead would push the fault downstream to whichever binding first dereferenced the settings,
where the message would name the cache rather than the actual cause.

### `Logger.fromEnv` no longer names a platform

It took `Env`, an ambient global from the runtime it was written for. It now takes
`{ LOG_LEVEL?: string } | null | undefined`, which is all it ever needed — and which an environment object, a
`process.env`, or a bare object literal all satisfy. This was the only real reference to a platform type in the whole
kernel; every other match was prose in a doc comment.

### `Signature` derives its key type from the runtime

`CryptoKey` is only an ambient global when a runtime-specific lib (`DOM`, `WebWorker`) is in scope, and this package
deliberately compiles with neither so anything runtime-specific fails the build. WebCrypto itself is part of the minimum
API every target runtime provides, so the value is always there — only the type name is not. The alias is derived from
`crypto.subtle` and never reaches the public surface.

### `systemDefaults.logging.service`

Was the name of the application this came from, now `'app'`. An application-specific value had no business being a
library default; the placeholder is deliberately generic so an un-overridden deployment reads as unconfigured rather
than as some other project.

## Kernel purity

An ESLint rule now forbids importing `@cloudflare/*`, `hono`, or `cloudflare:*` anywhere in `src/`. The boundary that
made this extraction possible is worth keeping enforced now that the code has somewhere to be extracted _to_.

## Tests

85 specs: the `configure`/`resolve` merge contract including both `ConfigurationError` paths, `timingSafeEqual` over the
cases an early return would get wrong, `Signature` sign/verify with a case per forgeable input, `Logger` threshold and
context handling, `Service` envelopes, the four `Noop*` capabilities, and `MissingCapabilityError` including the
cross-package `instanceof` a subclass depends on.

## Upgrading

Nothing to upgrade — this is the first release. A service moving off a vendored `src/core/` should follow the migration
guide published by its adapter package.