feat(web): show what the pipeline is doing while a job runs

"running" for two and a half minutes tells the user nothing. The job page now shows a
spinner, the elapsed time, and the pipeline step Nextflow is actually on.

- the API streams the Nextflow output into jobs.log as it arrives, instead of keeping it
  only when the run dies. Writes are throttled to one every 3s, or immediately when a new
  process starts, and are skipped for a job that has already finished, so a late line
  cannot overwrite the loader's result.
- web/src/lib/progress.ts formats the elapsed time and picks the latest [PROCESS] line.
  No percentage: the pipeline cannot honestly estimate one.
- the spinner animates only under prefers-reduced-motion: no-preference.

Verified on a live run: the page showed "VEP (tiny)" for the duration, then the variant
table replaced it on success.

Tests: api 53, web 20; ruff, mypy, svelte-check clean.

.svelte-kit/tsconfig.json

@@ -0,0 +1,50 @@
+{
+	"compilerOptions": {
+		"paths": {
+			"$app/types": [
+				"./types/index.d.ts"
+			]
+		},
+		"rootDirs": [
+			"..",
+			"./types"
+		],
+		"verbatimModuleSyntax": true,
+		"isolatedModules": true,
+		"lib": [
+			"esnext",
+			"DOM",
+			"DOM.Iterable"
+		],
+		"moduleResolution": "bundler",
+		"module": "esnext",
+		"noEmit": true,
+		"target": "esnext"
+	},
+	"include": [
+		"ambient.d.ts",
+		"env.d.ts",
+		"non-ambient.d.ts",
+		"./types/**/$types.d.ts",
+		"../vite.config.js",
+		"../vite.config.ts",
+		"../src/**/*.js",
+		"../src/**/*.ts",
+		"../src/**/*.svelte",
+		"../test/**/*.js",
+		"../test/**/*.ts",
+		"../test/**/*.svelte",
+		"../tests/**/*.js",
+		"../tests/**/*.ts",
+		"../tests/**/*.svelte"
+	],
+	"exclude": [
+		"../node_modules/**",
+		"../src/service-worker.js",
+		"../src/service-worker/**/*.js",
+		"../src/service-worker.ts",
+		"../src/service-worker/**/*.ts",
+		"../src/service-worker.d.ts",
+		"../src/service-worker/**/*.d.ts"
+	]
+}