refactor(geode): drop unused KtorRelay knobs (maxFrameBytes, maxAdminBodyBytes)

Ktor's WebSocket layer is unbounded by default, so [limits].max_ws_frame_bytes
was a strfry-parity tuning knob nobody actually used — drop the whole
LimitsSection from StaticConfig and the matching constructor param from
KtorRelay. The negentropy-large-corpus plan note is updated accordingly.

maxAdminBodyBytes is a real defense-in-depth cap (NIP-98 forces us to
read the body for the payload sha256 before we can authenticate, so an
unbounded read is a pre-auth DoS vector). Keep the cap, but stop
exposing it as an operator knob — it was never plumbed through to
StaticConfig and 1 MiB is ~1000× any plausible NIP-86 RPC payload.
Hardcoded at the Nip86HttpRoute construction site with the rationale
inline. Nip86HttpRoute.maxBodyBytes stays so tests can drive the 413
boundary.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

geode/plans/2026-05-07-negentropy-large-corpus.md

@@ -126,12 +126,13 @@ for unlimited). 500_000 is well above the floor. Pure config change in
 `NegSessionRegistry.open`; expose via `[negentropy].frame_size_limit`
 for operators who tune it down to fit smaller WS frame budgets.
 
-Note: `LimitsSection.max_ws_frame_bytes`
-(`geode/src/main/kotlin/com/vitorpamplona/geode/config/StaticConfig.kt:148`)
-applies to the WebSocket layer. After hex-encoding a 500_000-byte
-negentropy payload doubles to ~1_000_000 bytes on the wire; ensure
-`max_ws_frame_bytes` is at least 2 MB (or unlimited) in default
-config so the response isn't truncated by the WS layer.
+Note: Ktor's WebSocket layer does not impose a default frame cap, so a
+~1 MB hex-encoded negentropy payload is delivered intact. The
+`[limits].max_ws_frame_bytes` operator knob was removed once Ktor's
+unbounded default was confirmed to be sufficient — see the
+`refactor(geode): drop [limits] section` commit. If a reverse proxy
+is in front of the relay, the proxy's frame cap is the only thing
+that can still truncate.
 
 ### D — concurrent NEG-OPEN cap, shared with REQ