feat(lib): use new challenge creation flow (#749)

* feat(decaymap): add Delete method

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore(lib/challenge): refactor Validate to take ValidateInput

Signed-off-by: Xe Iaso <me@xeiaso.net>

* feat(lib): implement store interface

Signed-off-by: Xe Iaso <me@xeiaso.net>

* feat(lib/store): all metapackage to import all store implementations

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore(policy): import all store backends

Signed-off-by: Xe Iaso <me@xeiaso.net>

* feat(lib): use new challenge creation flow

Previously Anubis constructed challenge strings from request metadata.
This was a good idea in spirit, but has turned out to be a very bad idea
in practice. This new flow reuses the Store facility to dynamically
create challenge values with completely random data.

This is a fairly big rewrite of how Anubis processes challenges. Right
now it defaults to using the in-memory storage backend, but on-disk
(boltdb) and valkey-based adaptors will come soon.

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore(decaymap): fix documentation typo

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore(lib): fix SA4004

Signed-off-by: Xe Iaso <me@xeiaso.net>

* test(lib/store): make generic storage interface test adaptor

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: spelling

Signed-off-by: Xe Iaso <me@xeiaso.net>

* fix(decaymap): invert locking process for Delete

Signed-off-by: Xe Iaso <me@xeiaso.net>

* feat(lib/store): add bbolt store implementation

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: spelling

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: go mod tidy

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore(devcontainer): adapt to docker compose, add valkey service

Signed-off-by: Xe Iaso <me@xeiaso.net>

* fix(lib): make challenges live for 30 minutes by default

Signed-off-by: Xe Iaso <me@xeiaso.net>

* feat(lib/store): implement valkey backend

Signed-off-by: Xe Iaso <me@xeiaso.net>

* test(lib/store/valkey): disable tests if not using docker

Signed-off-by: Xe Iaso <me@xeiaso.net>

* test(lib/policy/config): ensure valkey stores can be loaded

Signed-off-by: Xe Iaso <me@xeiaso.net>

* Update metadata

check-spelling run (pull_request) for Xe/store-interface

Signed-off-by: check-spelling-bot <check-spelling-bot@users.noreply.github.com>
on-behalf-of: @check-spelling <check-spelling-bot@check-spelling.dev>

* chore(devcontainer): remove port forwards because vs code handles that for you

Signed-off-by: Xe Iaso <me@xeiaso.net>

* docs(default-config): add a nudge to the storage backends section of the docs

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore(docs): listen on 0.0.0.0 for dev container support

Signed-off-by: Xe Iaso <me@xeiaso.net>

* docs(policy): document storage backends

Signed-off-by: Xe Iaso <me@xeiaso.net>

* docs: update CHANGELOG and internal links

Signed-off-by: Xe Iaso <me@xeiaso.net>

* docs(admin/policies): don't start a sentence with as

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: fixes found in review

Signed-off-by: Xe Iaso <me@xeiaso.net>

---------

Signed-off-by: Xe Iaso <me@xeiaso.net>
Signed-off-by: check-spelling-bot <check-spelling-bot@users.noreply.github.com>

docs/docs/CHANGELOG.md

@@ -22,6 +22,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Add option for custom cookie prefix ([#732](https://github.com/TecharoHQ/anubis/pull/732))
 - Add translation for German language ([#741](https://github.com/TecharoHQ/anubis/pull/741))
 - Remove the "Success" interstitial after a proof of work challenge is concluded.
+- Anubis now has the concept of [storage backends](./admin/policies.mdx#storage-backends). These allow you to change how Anubis stores temporary data (in memory, on the disk, or in Valkey). If you run Anubis in an environment where you have a low amount of memory available for Anubis (eg: less than 64 megabytes), be sure to configure the [`bbolt`](./admin/policies.mdx#bbolt) storage backend.
+- The challenge issuance and validation process has been rewritten from scratch. Instead of generating challenge strings from request metadata (under the assumption that the values being compared against are stable), Anubis now generates random data for each challenge. This data is stored in the active [storage backend](./admin/policies.mdx#storage-backends) for up to 30 minutes. Fixes [#564](https://github.com/TecharoHQ/anubis/issues/564), [#746](https://github.com/TecharoHQ/anubis/issues/746), and other similar instances of this issue.
 - Add option for forcing a specific language ([#742](https://github.com/TecharoHQ/anubis/pull/742))
 - Add translation for Turkish language ([#751](https://github.com/TecharoHQ/anubis/pull/751))
 - Allow [Common Crawl](https://commoncrawl.org/) by default so scrapers have less incentive to scrape