lscache 1.0.x-dev

First release of LSCache — a Drupal.org-native integration for
LiteSpeed Cache, built around Drupal's native cache tag system and
the Purge framework.

This is the scaffold alpha. It covers the module's core
responsibility — emitting cache-tag headers on cacheable
responses — and sets up the architecture for the invalidation and
advanced features that land in subsequent releases.

## What works in this release

- **Response headers**: cacheable responses receive `X-LiteSpeed-Tag`
(Drupal cache tags) and `X-LiteSpeed-Cache-Control` (configurable
TTL) so LiteSpeed can cache and tag pages natively.
- **Admin form** at Configuration > Development > Performance >
LSCache, covering the enable flag, default TTL, per-site tag
prefix, and a debug mode.
- **Site prefix**: useful when multiple Drupal sites share one
LiteSpeed cache and need their tags scoped to avoid collisions.
- **lscache_purger submodule** registered as a Purge framework
plugin declaring support for the `tag` invalidation type. The
actual HTTP request that purges tags lands in 1.0.0-alpha2 —
see ROADMAP.md.

## What does NOT work yet

- **Tag invalidation**: `lscache_purger` registers the plugin but
currently marks every invalidation as failed. Enable the submodule
to get the skeleton registered in your Purge pipeline, but do not
rely on it to actually invalidate LiteSpeed until 1.0.0-alpha2.
- ESI, private cache, and vary cookies are all on the roadmap for
subsequent minor releases.

## Relationship to the LiteSpeed-published module

LiteSpeed Technologies publishes a Drupal module at
github.com/litespeedtech/lscache-drupal that is not on Drupal.org.
This module is a clean-room d.o-native alternative, built around
Drupal's cache tag system and the Purge framework so it integrates
with the rest of the Drupal contrib caching ecosystem out of the box.

## Requirements

- Drupal 10.3 or later, or Drupal 11.
- LiteSpeed Web Server or OpenLiteSpeed with LSCache enabled.
- drupal/purge (only to enable the lscache_purger submodule).

## Roadmap

See ROADMAP.md in the repository for the full release trajectory
through 1.3.0. Suggestions and patches welcome on the issue queue.