change how cid are handled

packages/meta-sort-core/src/kv/MetaCoreApiWriter.ts

@@ -59,7 +59,16 @@ export class MetaCoreApiWriter {
         for (const pair of pairs) {
             // pair.key is "file:<hash>/<field>"; strip the prefix+slash.
             const field = pair.key.slice(prefix.length + 1);
-            if (field) {
+            if (!field) continue;
+            // Sibling CIDs are stored as a bare-CID key-set (cids/<cid> =
+            // "true"), never as per-algorithm cid_* fields. Rewrite any
+            // legacy cid_* field (e.g. the in-memory cid_midhash256 primary
+            // id) into the key-set form so no deprecated field ever reaches a
+            // record. The CID is self-describing, so the algorithm in the
+            // field name is dropped. See METADATA_KEYS.md §2/§14.13.
+            if (field.startsWith('cid_') && pair.value) {
+                flat[`cids/${pair.value}`] = 'true';
+            } else {
                 flat[field] = pair.value;
             }
         }

packages/meta-sort-core/src/logic/fileProcessor/FileProcessorPiscina.ts

@@ -296,19 +296,16 @@ export class FileProcessorPiscina implements FileAnalyzerInterface{
             metadata.processingStatus = 'complete';
             this.database.set(filePath, metadata);
 
-            // STEP 5: Update metadata in KV with full hashes
+            // STEP 5: Update metadata in KV.
+            // Full hashes (sha2-256, sha1, …) are computed by the full-hash
+            // container plugin and written to meta-core directly as cids/<cid>
+            // members — they are not held in this in-memory metadata. The
+            // midhash256 is the primary id; on a (rare) midhash collision the
+            // file simply shares the record address until the plugin's
+            // distinct cids/* members disambiguate it.
             if (this.kvClient) {
                 try {
-                    // Choose hash ID: Use SHA-256 if collision detected, otherwise midhash256
-                    let hashId: string;
-                    if (collisionDetected && metadata['cid_sha2-256']) {
-                        // Collision: Use full SHA-256 as primary ID
-                        hashId = metadata['cid_sha2-256'];
-                        console.log(`   Using SHA-256 as primary ID for collision: ${hashId}`);
-                    } else {
-                        // Normal: Use midhash256 as primary ID
-                        hashId = midHash256;
-                    }
+                    const hashId = midHash256;
 
                     if (hashId) {
                         // Prepare metadata with filePath added
@@ -625,7 +622,7 @@ export class FileProcessorPiscina implements FileAnalyzerInterface{
         // Delete from KV if configured (using nested key architecture)
         if (this.kvClient && metadata) {
             try {
-                const hashId = metadata.cid_midhash256 || metadata['cid_sha2-256'] || metadata.cid_sha1 || metadata.cid_md5;
+                const hashId = metadata.cid_midhash256;
 
                 // Delete all properties for this file using nested key architecture
                 if (hashId) {

packages/meta-sort-core/src/types/FileMetadata.ts

@@ -18,4 +18,14 @@ export type ProcessingStatus = 'pending' | 'processing' | 'complete' | 'error';
 export interface FileMetadata extends HashMeta {
   /** Current status of file processing */
   processingStatus?: ProcessingStatus;
+
+  /**
+   * In-memory primary identifier: the file's midhash256 CID, computed in the
+   * light phase and used as the record address (hashId) throughout meta-sort.
+   * This is an in-process working field only — it is persisted to the record
+   * as a `cids/<cid>` key-set member (by the meta-core watcher and the KV
+   * writer's cid_* → cids/ transform), never as a named `cid_midhash256`
+   * field. See METADATA_KEYS.md §1/§14.13.
+   */
+  cid_midhash256?: string;
 }