point the skill at where a board's effect names belong, not at Go code

The skill told an agent that a name it observes on the board "goes in the board's
file in `internal/rgb`". There is no such file: internal/rgb holds the catalog
type, the definition parser and the colour code, and a grep for the Impact 80's
names finds nothing in it. It is also the one instruction in the repository that
produces exactly what the project was built to stop: a transcribed name list
beside the vendor's file, which is two places to update one name, and is how the
names here drifted from the ones Wobkey publishes.

A name goes in that board's definition file in definitions/, which
definitions/README.md already states, and which takes effect after a rebuild.

Also correct what the firmware does with effect ID 0 on logo and side. The skill
said it "refuses" the ID, which reads as an error; nothing is refused. The
firmware reads 0 as "lighting off", leaves the mode register where it was, and
the effect that was running keeps running. That is the distinction the sentence
was making, and the wording lost it.

.claude/skills/qmk-rgb/SKILL.md

@@ -87,8 +87,13 @@ board is refused by name.
 
 Never write an effect name into this repo that no source states. Either the
 vendor's file names it, or the user has looked at the board and named what they
-see — in which case it is a tool name, it goes in the board's file in
-`internal/rgb`, and the comment says it was measured.
+see — in which case it is a tool name, it goes in that board's definition file
+in `definitions/`, and the comment says it was measured. No name belongs in Go
+code: there is no hand-written catalog anywhere in `internal/`, because a list
+beside the vendor's file is two places to update one name, and that is how the
+names here drifted from the ones Wobkey publishes. `definitions/README.md` says
+which files belong in that directory; a file added there takes effect after a
+rebuild.
 
 ## Zone behavior
 
@@ -133,8 +138,10 @@ user that the tool's own output did not confirm.
 
 ## Compatibility aliases
 
-- `off` → `none`, but on `logo` and `side` the firmware refuses effect ID 0 and
-  leaves the running effect alone; `disable` is what turns a channel off
+- `off` → `none`, but on `logo` and `side` the firmware reads effect ID 0 as
+  "lighting off" and leaves the mode register where it was, so the running
+  effect keeps running; `disable` is what turns a channel off, because it also
+  writes brightness 0
 - `breathe` → `breathing`
 - `rainbow` → varies by zone (resolves automatically)
 - `solid` → varies by zone (resolves automatically)