Parse two word directed commands

[tekstrand]

What

1. Parses two word directed commands like MSG TO: and QUERY MSGS whole instead of stopping at the first word
2. Adds Js8Commands, a Kotlin copy of the kDirectedCmds table in varicode.cpp, to do the matching. Longest name first, and unknown text falls back to the old single token shape
3. Removes the MSG inline-payload extraction and matches the branch on the two commands it handles
4. Adds a unit test that reads kDirectedCmds out of varicode.cpp and fails when the Kotlin table drifts from it

Why

The store and forward work I have planned builds on this.

1. The parser took the command as one whitespace token, so MSG TO: arrived as MSG with the destination glued to the payload, and QUERY MSGS arrived as QUERY.
2. kDirectedCmds is the table the C++ side packs and unpacks against, but the unit tests run on the host JVM where the native library can't load, so the parser needs its own copy. Freetext comes through the same parser, so text that is not a command has to come out exactly as it did before.
3. The extraction handled a command token with the payload stuck to it, like MSGHELLO. That shape can't reach the parser: directed frames unpack their command from the table by index and the JNI joins the parts with explicit spaces. It was dead code until now, but MSG TO: parsing whole would have set it off and put a stray TO: in the message text.
4. Copies drift. The test parses varicode.cpp at test time, so a divergence fails the build instead of becoming a wire format bug.

Test

1. ./gradlew :app:testDebugUnitTest (20 tests, 8 of them new, all passing)
2. To watch the drift guard work, rename any command in kDirectedCmds in varicode.cpp and rerun. kotlinTableMatchesNativeVaricodeTable fails and prints the disagreement.