Forward-merge the mesh discovery module rename (directory, exported types, and
internal lookup-stem terminology) onto the next wire-format line. next's
divergent lookup wire and core content is preserved under the new proto/lookup
path, with the same terminology sweep applied to its next-only lines.
Rename src/proto/discovery to src/proto/lookup and bring the module's naming
onto the lookup stem, matching its concept: a mesh lookup of a node's
coordinates from its pubkey, sent into the mesh as a bloom-filter-guided
multicast request that returns a unicast response with the coordinates.
- the module directory and its declaration (proto::discovery -> proto::lookup)
- exported types: DiscoveryAction -> LookupAction, DiscoveryBackoff ->
LookupBackoff, DiscoveryForwardRateLimiter -> LookupForwardRateLimiter,
MAX_RECENT_DISCOVERY_REQUESTS -> MAX_RECENT_LOOKUP_REQUESTS, and the Discovery
state struct -> Lookup
- internal terminology: doc comments, the "overlay-lookup" phrasing, the
empty_discovery/suppressing_discovery test helpers, and the disc
parameter/variable all take the lookup names
- the already-lookup-named wire types (LookupRequest/LookupResponse) are unchanged
Behavior-neutral: no wire bytes or decision logic change. Two references are
intentionally kept as "discovery": the still-named node::handlers::discovery
shell module and the node.discovery.* config keys, which belong to the broader
disambiguation of the shell, config, and metric surfaces still to come.