Step 1: SemanticTokenStore/InlayHintStore::for_uri (+ repair main)

Adds the URI-only store views the semantic-frontend producer arc
needs. The stores key by (server, uri); the producer only knows the
document, so `for_uri` scans by uri and picks the lowest *numeric*
server id deterministically (HashMap order is otherwise
nondeterministic; lowest id == oldest/primary attachment). Blending
multiple servers' styling on one buffer is a deferred open question.

Inlay-hint `for_uri` returns no server: Step 0 established inlay
positions are already pmacs byte offsets by the time they hit the
store (the absorb path's inbound_converted rewrites the
Position-shaped InlayHint.position), so the producer needs no
per-server encoding for them. Semantic tokens differ — start/length
stay UTF-16, hence the (server, response) tuple so the matching
LspManager::semantic_style_context can resolve encoding + legend.

Also repairs main: PR #28 (file-watch) inadvertently swept in the
uncommitted lsp.rs side of this work — SemanticStyleContext and
semantic_style_context, which call store.for_uri — without these
defining accessors, leaving main referencing an undefined method
(no method `for_uri`). This commit supplies the missing definitions,
so main compiles again.

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

src/inlay_hint.rs

@@ -197,6 +197,28 @@ impl InlayHintStore {
     pub fn get(&self, key: &InlayHintKey) -> Option<&InlayHintResponse> {
         self.by_key.get(key)
     }
+
+    /// Look up the entry for `uri` regardless of which server keyed
+    /// it. Mirrors [`crate::semantic_tokens::SemanticTokenStore::for_uri`]:
+    /// the lowest (numeric) server id wins for determinism across
+    /// `HashMap` order. No server is returned — unlike semantic
+    /// tokens, inlay-hint positions are already pmacs byte offsets by
+    /// the time they reach the store (the absorb path's
+    /// `inbound_converted` rewrites the `Position`-shaped
+    /// `InlayHint.position`), so the producer needs no per-server
+    /// encoding to place them.
+    #[must_use]
+    pub fn for_uri(&self, uri: &str) -> Option<&InlayHintResponse> {
+        self.by_key
+            .iter()
+            .filter(|(k, _)| k.uri == uri)
+            .min_by_key(|(k, _)| {
+                k.server
+                    .parse::<u64>()
+                    .map_or((u64::MAX, k.server.as_str()), |n| (n, ""))
+            })
+            .map(|(_, v)| v)
+    }
 }
 
 /// Cheaply-cloneable shared handle.
@@ -291,4 +313,29 @@ mod tests {
         s.clear(&key);
         assert!(s.get(&key).is_none());
     }
+
+    #[test]
+    fn for_uri_filters_by_uri_and_picks_lowest_server() {
+        let mk = |label: &str| InlayHintResponse {
+            hints: vec![InlayHint {
+                line: 0,
+                col: 0,
+                label: label.into(),
+                kind: None,
+                padding_left: false,
+                padding_right: false,
+                tooltip: None,
+            }],
+        };
+        let mut s = InlayHintStore::new();
+        s.set(InlayHintKey::new("10", "file:///a"), mk("s10"));
+        s.set(InlayHintKey::new("9", "file:///a"), mk("s9"));
+        s.set(InlayHintKey::new("2", "file:///b"), mk("s2"));
+
+        // Lowest *numeric* server id wins ("9" < "10" numerically,
+        // not lexicographically).
+        assert_eq!(s.for_uri("file:///a").unwrap().hints[0].label, "s9");
+        assert_eq!(s.for_uri("file:///b").unwrap().hints[0].label, "s2");
+        assert!(s.for_uri("file:///nope").is_none());
+    }
 }

src/semantic_tokens.rs

@@ -263,6 +263,39 @@ impl SemanticTokenStore {
     pub fn get(&self, key: &SemanticTokenKey) -> Option<&SemanticTokensResponse> {
         self.by_key.get(key)
     }
+
+    /// Look up the entry for `uri` regardless of which server keyed
+    /// it, returning `(server, response)`. The store keys by
+    /// `(server, uri)` but the semantic-render producer only knows the
+    /// document; this is the URI-only view the diagnostics store
+    /// (`DiagnosticStore`) offers natively.
+    ///
+    /// When more than one server has tokens for the same URI the
+    /// **lowest server id** wins, chosen by numeric value so the
+    /// result is deterministic across `HashMap` iteration order
+    /// (server ids are assigned monotonically, so the lowest is the
+    /// oldest / primary attachment). Blending styling from multiple
+    /// servers on one buffer is a deliberately deferred open question
+    /// — see `docs/semantic-frontend-protocol.md`.
+    #[must_use]
+    pub fn for_uri(&self, uri: &str) -> Option<(&str, &SemanticTokensResponse)> {
+        self.by_key
+            .iter()
+            .filter(|(k, _)| k.uri == uri)
+            .min_by_key(|(k, _)| server_sort_key(&k.server))
+            .map(|(k, v)| (k.server.as_str(), v))
+    }
+}
+
+/// Order key for picking a representative server: numeric if the id
+/// parses (the normal case — ids are decimal `LspServerId::raw`),
+/// else a max sentinel so unparsable ids sort last but the lookup
+/// still yields *something* rather than nothing.
+fn server_sort_key(server: &str) -> (u64, &str) {
+    match server.parse::<u64>() {
+        Ok(n) => (n, ""),
+        Err(_) => (u64::MAX, server),
+    }
 }
 
 /// Cheaply-cloneable shared handle.
@@ -392,6 +425,37 @@ mod tests {
         assert!(s.get(&key).is_none());
     }
 
+    #[test]
+    fn for_uri_filters_by_uri_and_picks_lowest_server() {
+        let mk = |tok_type: u32| SemanticTokensResponse {
+            tokens: vec![SemanticToken {
+                line: 0,
+                start: 0,
+                length: 1,
+                token_type: tok_type,
+                token_modifiers: 0,
+            }],
+            result_id: None,
+            raw: vec![0, 0, 1, tok_type, 0],
+        };
+        let mut s = SemanticTokenStore::new();
+        // Same URI under two servers; ids deliberately inserted so
+        // numeric (not lexicographic: "10" < "9" as strings) ordering
+        // is what makes the test meaningful.
+        s.set(SemanticTokenKey::new("10", "file:///a"), mk(10));
+        s.set(SemanticTokenKey::new("9", "file:///a"), mk(9));
+        s.set(SemanticTokenKey::new("2", "file:///b"), mk(2));
+
+        let (server, resp) = s.for_uri("file:///a").expect("entry for /a");
+        assert_eq!(server, "9", "lowest *numeric* server id wins");
+        assert_eq!(resp.tokens[0].token_type, 9);
+
+        let (server_b, _) = s.for_uri("file:///b").expect("entry for /b");
+        assert_eq!(server_b, "2");
+
+        assert!(s.for_uri("file:///nope").is_none());
+    }
+
     #[test]
     fn from_lsp_value_retains_raw() {
         let v = json!({ "resultId": "r1", "data": [0, 0, 4, 1, 1, 0, 5, 3, 2, 0] });