perf(javascript)!: stop repeating the semantic identifier strategy per fact (#1474)

Every semantic graph node and relation carried an identifier_strategy
object whose schema admits exactly one value per record type. The
constant made up about 9% of analyze_javascript_application output
(Obsidian app.asar: 12.04 MB to 10.96 MB), and semantic traces repeated
it on every returned fact.

The node_id and relation_id schema descriptions now state how each
identifier is derived.

BREAKING CHANGE: Semantic graph nodes and relations no longer include
identifier_strategy, and relation IDs no longer hash that constant.
Evidence recorded by earlier versions does not validate against the new
semantic graph schema.

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

src/domain/javascript/javascriptSemanticGraphSchemas.ts

@@ -233,11 +233,9 @@ export const javaScriptSemanticNodeInputSchema = z.strictObject({
 export const javaScriptSemanticNodeSchema =
   javaScriptSemanticNodeInputSchema.extend({
     evidence: javaScriptSemanticEvidenceReferenceSchema,
-    node_id: semanticNodeIdSchema,
-    identifier_strategy: z.strictObject({
-      strategy: z.literal("semantic-content-sha256"),
-      stability: z.literal("artifact-version"),
-    }),
+    node_id: semanticNodeIdSchema.describe(
+      "SHA-256 of the node kind and identity; stable for one artifact version.",
+    ),
   });
 
 /** One directed semantic relationship before its ID is derived. */
@@ -254,11 +252,9 @@ export const javaScriptSemanticRelationInputSchema = z.strictObject({
 export const javaScriptSemanticRelationSchema =
   javaScriptSemanticRelationInputSchema.extend({
     evidence: javaScriptSemanticEvidenceReferenceSchema,
-    relation_id: semanticRelationIdSchema,
-    identifier_strategy: z.strictObject({
-      strategy: z.literal("semantic-content-sha256"),
-      stability: z.literal("relationship-exact"),
-    }),
+    relation_id: semanticRelationIdSchema.describe(
+      "SHA-256 of the exact relation content, including its evidence reference.",
+    ),
   });
 
 /** Reasons semantic analysis can leave an explicit frontier. */