refactor(relay): drop dead Typesense config + correct stale search comments

The Typesense search backend was replaced by Postgres FTS in this rewrite,
but two vestiges remained in live code:

- `Config.typesense_url` / `Config.typesense_key` were still parsed from
  `TYPESENSE_URL` / `TYPESENSE_API_KEY` and stored on the struct, yet read
  nowhere outside config.rs. Removed the fields, env parsing, and struct init.
- Several doc/inline comments still described the search path as hitting
  Typesense (req.rs NIP-50 handler, bridge.rs post-filter rationale). The
  behavior is unchanged but the engine is Postgres FTS; corrected the naming
  so the comments match the code.

Kept genuinely historical references intact (event.rs note that the old
index_event worker is gone; query.rs/schema provenance of the legacy
__global__ sentinel and the FTS migration).

cargo check -p buzz-relay green.

Co-authored-by: Tyler Longwell <tlongwell@block.xyz>
Signed-off-by: Tyler Longwell <tlongwell@block.xyz>

Cargo.toml

@@ -79,7 +79,7 @@ anyhow    = "1"
 uuid    = { version = "1", features = ["v4", "serde"] }
 chrono  = { version = "0.4", features = ["serde"] }
 
-# HTTP client (webhook delivery, Typesense indexing)
+# HTTP client (webhook delivery)
 reqwest = { version = "0.13", features = ["json", "rustls"], default-features = false }
 
 # Cryptography

crates/buzz-relay/src/api/bridge.rs

@@ -773,7 +773,7 @@ pub async fn count_events(
 /// Decide whether a search hit should be returned to the caller.
 ///
 /// Mirrors the WS NIP-50 path's post-filter step in `handlers/req.rs`:
-/// Typesense receives only the kind/authors/time pushdown, so any other filter
+/// the FTS backend receives only the kind/authors/time pushdown, so any other filter
 /// constraint (`#p`, `#h`, `#e`, `#d`, `ids`, …) must be enforced here against
 /// the full stored event. Without this, an authorized engram search such as
 /// `{"kinds":[30174],"#p":[self]}` would leak text-matching envelopes whose
@@ -1571,7 +1571,7 @@ mod tests {
     /// Setup: two engram envelopes by different agents for different owners.
     /// An authorized search for `{kinds:[30174], #p:[owner_a]}` would be
     /// approved by the engram gate (owner_a is querying engrams addressed to
-    /// them). Typesense's pushdown only carries `kind:=[30174]`, so the
+    /// them). The FTS pushdown only carries `kind:=[30174]`, so the
     /// envelope for owner_b can come back as a text-match hit. The post-filter
     /// in `search_hit_accepted` must reject it.
     #[test]
@@ -1602,7 +1602,7 @@ mod tests {
     }
 
     /// `authors=[agent_a]` search must not return an envelope authored by agent_b,
-    /// even if Typesense's text match would otherwise surface it. (Typesense does
+    /// even if the FTS text match would otherwise surface it. (The FTS query does
     /// carry an `authors` pushdown today, so this is defence-in-depth; mirroring
     /// the WS contract.)
     #[test]

crates/buzz-relay/src/config.rs

@@ -31,10 +31,6 @@ pub struct Config {
     pub database_url: String,
     /// Redis connection URL used by the pub/sub manager.
     pub redis_url: String,
-    /// Typesense search server URL.
-    pub typesense_url: String,
-    /// Typesense API key.
-    pub typesense_key: String,
     /// Public WebSocket URL of this relay, advertised in NIP-11.
     pub relay_url: String,
     /// Maximum number of concurrent WebSocket connections.
@@ -177,12 +173,6 @@ impl Config {
         let redis_url =
             std::env::var("REDIS_URL").unwrap_or_else(|_| "redis://localhost:6379".to_string());
 
-        let typesense_url =
-            std::env::var("TYPESENSE_URL").unwrap_or_else(|_| "http://localhost:8108".to_string());
-
-        let typesense_key =
-            std::env::var("TYPESENSE_API_KEY").unwrap_or_else(|_| "buzz_dev_key".to_string());
-
         let relay_url =
             std::env::var("RELAY_URL").unwrap_or_else(|_| "ws://localhost:3000".to_string());
 
@@ -400,8 +390,6 @@ impl Config {
             bind_addr,
             database_url,
             redis_url,
-            typesense_url,
-            typesense_key,
             relay_url,
             max_connections,
             max_concurrent_handlers,

crates/buzz-relay/src/handlers/req.rs

@@ -190,7 +190,7 @@ pub async fn handle_req(
         }
     }
 
-    // Search filters hit Typesense and return historical hits, then EOSE.
+    // Search filters hit Postgres FTS and return historical hits, then EOSE.
     // They are not registered for fan-out. The sensitive-kind gates above
     // already ran, so an authed member cannot use search to bypass author/#p
     // rules for kind:30174 or other globally-stored gated kinds.
@@ -374,9 +374,9 @@ pub async fn handle_req(
     );
 }
 
-/// Handle a NIP-50 search REQ: query Typesense, fetch full events, deliver results, EOSE.
+/// Handle a NIP-50 search REQ: query Postgres FTS, fetch full events, deliver results, EOSE.
 /// Search subscriptions are one-shot — no persistent subscription is registered.
-/// Maximum Typesense pages to fetch per filter (prevents unbounded loops).
+/// Maximum FTS pages to fetch per filter (prevents unbounded loops).
 const MAX_SEARCH_PAGES: u32 = 10;
 
 /// Resolve request-local channel access, repairing a stale cache-negative.