Use sqlite-vec extension instead of chromadb for embeddings (#14163)

* swap sqlite_vec for chroma in requirements

* load sqlite_vec in embeddings manager

* remove chroma and revamp Embeddings class for sqlite_vec

* manual minilm onnx inference

* remove chroma in clip model

* migrate api from chroma to sqlite_vec

* migrate event cleanup from chroma to sqlite_vec

* migrate embedding maintainer from chroma to sqlite_vec

* genai description for sqlite_vec

* load sqlite_vec in main thread db

* extend the SqliteQueueDatabase class and use peewee db.execute_sql

* search with Event type for similarity

* fix similarity search

* install and add comment about transformers

* fix normalization

* add id filter

* clean up

* clean up

* fully remove chroma and add transformers env var

* readd uvicorn for fastapi

* readd tokenizer parallelism env var

* remove chroma from docs

* remove chroma from UI

* try removing custom pysqlite3 build

* hard code limit

* optimize queries

* revert explore query

* fix query

* keep building pysqlite3

* single pass fetch and process

* remove unnecessary re-embed

* update deps

* move SqliteVecQueueDatabase to db directory

* make search thumbnail take up full size of results box

* improve typing

* improve model downloading and add status screen

* daemon downloading thread

* catch case when semantic search is disabled

* fix typing

* build sqlite_vec from source

* resolve conflict

* file permissions

* try build deps

* remove sources

* sources

* fix thread start

* include git in build

* reorder embeddings after detectors are started

* build with sqlite amalgamation

* non-platform specific

* use wget instead of curl

* remove unzip -d

* remove sqlite_vec from requirements and load the compiled version

* fix build

* avoid race in db connection

* add scale_factor and bias to description zscore normalization

web/src/components/card/SearchThumbnail.tsx

@@ -52,12 +52,11 @@ export default function SearchThumbnail({
         className="absolute inset-0"
         imgLoaded={imgLoaded}
       />
-      <div className={`${imgLoaded ? "visible" : "invisible"}`}>
+      <div className={`size-full ${imgLoaded ? "visible" : "invisible"}`}>
         <img
           ref={imgRef}
           className={cn(
-            "size-full select-none opacity-100 transition-opacity",
-            searchResult.search_source == "thumbnail" && "object-contain",
+            "size-full select-none object-cover object-center opacity-100 transition-opacity",
           )}
           style={
             isIOS