fix(desktop): support PAYDAY: The Heist Update 23 loaders - #151

Summary

PAYDAY: The Heist Update 23 (October 20, 2026) changed how both of its loaders work, and Modrex was getting both wrong.

• mod_overrides is built into the game. The update reads assets/mod_overrides itself and adds DB:create_entry and DB:remove_entry, which is everything PDTHModOverrides (ModWorkshop 53474) backported. Its DINPUT8.dll proxy also has the same name as the proxy DAHM now ships, so installing it from Modrex would replace DAHM's proxy and stop DAHM from loading.
• DAHM was rewritten for the update. The current release is dinput8.dll plus pdthhook.dll and no longer ships lightfx.dll. Its author says the old hook does not work with the new build. Modrex looked for lightfx.dll, so a fresh DAHM install read as missing, and a broken old install read as installed.

Changes:

• Replace the game-specific pdth_overrides loader kind with a generic built_in package kind. A dependency on a built_in mod page always reads as met, and nothing is installed for it. The PDTH package declares 53474 with it, so the game fact lives only in package.toml. A built_in loader with no mod ids fails package validation.
• Detect DAHM by pdthhook.dll. The dinput8.dll proxy name is not unique to DAHM.
• Remove stale loader DLL names from renderer comments, and update AGENTS.md, the site docs, the generated package reference and CHANGELOG.

Evidence: the Steam Update 23 changelog, the DAHM author's announcement on the dahm4pd Steam group, and the current DAHM archive itself. The pdthhook.dll strings include "using the game's built-in mod_overrides support" and "file(s) from assets/mod_overrides".

Not included: removing an existing PDTHModOverrides install. Its hardcoded hook offset is likely broken on the new build, but no crash has been reported yet.

Type of change

• Application/code
• Translation
• Documentation
• Other

Translation (if applicable)

• Language:
• Locale code:

See the translation guide.

Validation

• Full local repository checks (bun checks)
• Relevant local checks
• CI only
• Not applicable

Details:

• bun checks at the branch head: everything passed except one renderer test, which timed out. That test (App.test.tsx, PAYDAY 3 Nexus source restore) is unrelated to this change, and it passed 3/3 on its own. The full renderer suite then passed 623/623.
• cargo test passed at the first commit on its own and at the branch head (1034 unit tests plus the package validation and reference export tests).
• cargo clippy --all-targets -- -D warnings is clean.
• No dependency changes.
• preview/fixtures/loaders.json was edited by hand to match list_loaders(), because its exporter needs ModWorkshop, which was returning 502.