Rename app from oAI to Confab

"oAI" reads as easily confused with OpenAI, both visually and in
casual conversation. Renamed to "Confab" throughout: Xcode
target/scheme/bundle ID (com.oai.Confab), Info.plist and Help Book
identity, all user-facing UI text, internal Log subsystem and color
identifiers, localization catalogs (6 languages, including a proper
reworded/retranslated Intel-deprecation notice), Help Book HTML
content, and docs (README/DEVELOPMENT/PRIVACY/SECURITY).

Deliberately cosmetic-only: the on-disk data folder
(~/Library/Application Support/oAI/), database/backup filenames,
Keychain service identifiers, and EncryptionService's key-derivation
inputs are all left untouched so existing conversations, settings,
and stored API keys survive the update with zero migration and no
re-entering credentials. Verified live: a real signed build
successfully decrypted a stored API key and loaded an existing
conversation database after the bundle ID change.

Also includes a small already-completed, previously uncommitted
model-release-date feature (ModelInfo/OpenRouterModels/
OpenRouterProvider/ModelInfoView) that happened to share several
files with this rename.

Gitignored on this branch and updated on disk but not part of this
commit: CLAUDE.md, RELEASE_NOTES.md, and the build*.sh scripts.

oAITests/GitSyncServiceTests.swift

@@ -7,7 +7,7 @@
 
 import Testing
 import Foundation
-@testable import oAI
+@testable import Confab
 
 @Suite("GitSyncService pure helpers")
 struct GitSyncServiceTests {