feat(library/providers): let a provider say how to recognize its games

A plugin's titles launch through the provider's own client, which hands off and
exits — so the host had nothing left to watch, and both lifetime behaviors went
quiet for exactly the entries a provider contributes. A `ProviderEntry` (and a
manual custom entry) may now carry an optional `detect` hint: install dir, exe,
or process name.

It is deliberately a subset of what the host tracks internally. A Steam appid or
a launcher's environment marker are things the host discovers for itself and
would be meaningless — or dangerous — to take on someone's word; where a title
is installed is something only the provider knows. The host's own findings win
where both exist, so a stale export can never redirect the matcher, and a blank
field is treated as absent rather than as "match everything" — an empty install
dir would otherwise prefix-match every process on the box, and this feature can
end processes.

`process_name` is the weakest of the three and the only one typed by hand, so it
is matched case-insensitively against the image's file name and nothing else:
`retroarch` finds RetroArch, not a helper whose name merely starts the same way,
and not a script that happens to live in a `retroarch/` directory. The
never-adopt-a-pre-existing-process rule still bounds it.

Also: the tray summary gains the running-game row (with the closing-in countdown
for a game whose client is gone — visible at the machine without opening the
console), the SDK mirrors the `game.*` events, and its generated client catches
up with the endpoints Phase 1 added.

Gates on .21: check + clippy --all-targets clean, 299 tests, fmt CI-parity,
openapi regenerated (GameEntry still carries no `detect` outbound); SDK tsc +
54 tests green.

plugin-kit/package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@punktfunk/plugin-kit",
-	"version": "0.1.4",
+	"version": "0.2.0",
 	"description": "Effect-based framework for punktfunk plugins: lifecycle runtime, config/state, sync engine, UI serving, CLI scaffold, and browser helpers.",
 	"type": "module",
 	"license": "MIT OR Apache-2.0",