All three answer different questions, and once you see which question each one asks the rule is obvious.
Annotation — const config: Config = {...}. This says "treat this variable as a Config". It checks the literal, and it also replaces what the compiler knows with the declared type. So if Config is Record<string, string>, indexing gives you string and the specific keys are gone. That is not a bug, it is the point: you asked for the general type.
Cast — const config = {...} as Config. This says "stop checking, I am telling you what this is". It is an assertion, not a check. It will accept a wrong shape as long as it is not wildly unrelated, which is exactly the typo problem you described — and your fear is correct, this is the dangerous one. A cast is a comment claiming something the compiler no longer verifies.
satisfies — const config = {...} satisfies Config. This says "check this against Config, but keep what you actually wrote". You get the validation of the annotation and the specific literal type. Typos are errors, missing keys are errors, and indexing still gives you the exact keys and the exact value types.
So the rule: satisfies by default. Annotation when you genuinely want the wider type. as almost never.