refactor(shared-rss): extract RSS parsing + Readability into one package

news-ingester and apps/api both shipped their own copy of rss-parser
+ jsdom + Readability glue. Single source now in packages/shared-rss.
Adds discoverFeeds (rel=alternate + common-paths probe) and validateFeed
which News Research will use. JSDOM virtualConsole is silenced once,
in the package, instead of in two parallel call sites.

- packages/shared-rss: parse, extract, discover, validate
- services/news-ingester: drop local parsers, depend on @mana/shared-rss
- apps/api: drop @mozilla/readability + jsdom direct deps, use shared

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/shared-rss/package.json

@@ -0,0 +1,32 @@
+{
+	"name": "@mana/shared-rss",
+	"version": "0.1.0",
+	"private": true,
+	"sideEffects": false,
+	"description": "RSS/Atom parsing, article extraction, and feed discovery primitives.",
+	"main": "./src/index.ts",
+	"types": "./src/index.ts",
+	"exports": {
+		".": "./src/index.ts",
+		"./parse": "./src/parse.ts",
+		"./extract": "./src/extract.ts",
+		"./discover": "./src/discover.ts",
+		"./validate": "./src/validate.ts",
+		"./types": "./src/types.ts"
+	},
+	"scripts": {
+		"type-check": "tsc --noEmit",
+		"clean": "rm -rf dist",
+		"lint": "eslint ."
+	},
+	"dependencies": {
+		"@mozilla/readability": "^0.5.0",
+		"jsdom": "^25.0.1",
+		"rss-parser": "^3.13.0"
+	},
+	"devDependencies": {
+		"@types/jsdom": "^21.1.7",
+		"@types/node": "^24.10.1",
+		"typescript": "^5.9.3"
+	}
+}