feat: migrate frontend React 18 → Svelte 5 + SvelteKit

Core logic portable (economy, balance, cosmetics, migrateSave) — zero rewrite.
136 tests green, identiques. Backend inchangé.

- Svelte 5 runes stores (game, auth, toast) remplacent Zustand
- SvelteKit adapter-static SPA (dist/ output, fallback index.html)
- Tailwind v4 conservé, design system .gp-* porté
- Transitions natives : slide, fly, scale, fade sur toute l'UI
- Sidebar tabbée (Production/Evolution/Collection) + CollapsiblePanel
- Mobile bottom sheet avec FAB toggle + backdrop blur
- Click particles réactifs Svelte (plus de DOM impératif)
- TadpoleSprite bounce + glow ring au clic
- Guide refait en accordéon, Achievements avec filtres
- a11y : focus-visible, Escape modals, aria-current, aria-labels
- CI/CD adapté (tests + build + rsync)
- Build 504K (vs ~1.2MB React)

Frontend/static/robots.txt

@@ -0,0 +1,150 @@
+Sitemap: https://clickerz.tetardtek.com/sitemap.xml
+
+User-agent: AlphaSeoBot 
+User-agent: AlphaSeoBot-SA 
+User-agent: Baiduspider-favo
+User-agent: Baiduspider-cpro
+User-agent: Baiduspider-ads
+User-agent: Baidu
+User-agent: Baiduspider-news
+User-agent: Baiduspider-video
+User-agent: Baiduspider-image
+User-agent: Baiduspider
+User-agent: BLEXBot
+User-agent: 008
+User-agent: Alexibot
+User-agent: AlvinetSpider
+User-agent: Antenne Hatena
+User-agent: ApocalXExplorerBot
+User-agent: asterias
+User-agent: BackDoorBot/1.0
+User-agent: BizInformation
+User-agent: Black Hole
+User-agent: BlowFish/1.0
+User-agent: BotALot
+User-agent: BuiltBotTough
+User-agent: Bullseye/1.0
+User-agent: BunnySlippers
+User-agent: Cegbfeieh
+User-agent: CheeseBot
+User-agent: CherryPicker
+User-agent: CherryPickerElite/1.0
+User-agent: CherryPickerSE/1.0
+User-agent: CopyRightCheck
+User-agent: cosmos
+User-agent: Crescent
+User-agent: Crescent Internet ToolPak HTTP OLE Control v.1.0
+User-agent: DISCo Pump 3.1
+User-agent: DittoSpyder
+User-agent: dotbot
+User-agent: EmailCollector
+User-agent: EmailSiphon
+User-agent: EmailWolf
+User-agent: EroCrawler
+User-agent: Exabot
+User-agent: ExtractorPro
+User-agent: Flamingo_SearchEngine
+User-agent: Foobot
+User-agent: grapeshot
+User-agent: Harvest/1.5
+User-agent: hloader
+User-agent: httplib
+User-agent: HTTrack
+User-agent: HTTrack 3.0
+User-agent: humanlinks
+User-agent: Igentia
+User-agent: InfoNaviRobot
+User-agent: JennyBot
+User-agent: JikeSpider
+User-agent: Kenjin Spider
+User-agent: LexiBot
+User-agent: libWeb/clsHTTP
+User-agent: LinkextractorPro
+User-agent: LinkScan/8.1a Unix
+User-agent: LinkWalker
+User-agent: lwp-trivial
+User-agent: lwp-trivial/1.34
+User-agent: Mata Hari
+User-agent: Microsoft URL Control - 5.01.4511
+User-agent: Microsoft URL Control - 6.00.8169
+User-agent: MIIxpc
+User-agent: MIIxpc/4.2
+User-agent: Mister PiX
+User-agent: MLBot
+User-agent: moget
+User-agent: moget/2.1
+User-agent: MS Search 4.0 Robot
+User-agent: MS Search 5.0 Robot
+User-agent: Naverbot
+User-agent: NetAnts
+User-agent: NetAttache
+User-agent: NetMechanic
+User-agent: NICErsPRO
+User-agent: Offline Explorer
+User-agent: Openfind
+User-agent: OpenindexSpider
+User-agent: ProPowerBot/2.14
+User-agent: ProWebWalker
+User-agent: psbot
+User-agent: QuepasaCreep
+User-agent: QueryN Metasearch
+User-agent: RepoMonkey
+User-agent: RMA
+User-agent: SightupBot
+User-agent: SiteBot
+User-agent: SiteSnagger
+User-agent: SiteSucker
+User-agent: Sogou web spider
+User-agent: sosospider
+User-agent: SpankBot
+User-agent: spanner
+User-agent: Speedy
+User-agent: suggybot
+User-agent: SuperBot
+User-agent: SuperBot/2.6
+User-agent: suzuran
+User-agent: Szukacz/1.4
+User-agent: Teleport
+User-agent: Telesoft
+User-agent: The Intraformant
+User-agent: TheNomad
+User-agent: TightTwatBot
+User-agent: Titan
+User-agent: toCrawl/UrlDispatcher
+User-agent: TosCrawler
+User-agent: trendictionbot
+User-agent: True_Robot
+User-agent: True_Robot/1.0
+User-agent: turingos
+User-agent: TurnitinBot
+User-agent: UrlPouls
+User-agent: URLy Warning
+User-agent: VCI
+User-agent: Web Image Collector
+User-agent: WebAuto
+User-agent: WebBandit
+User-agent: WebBandit/3.50
+User-agent: WebCopier
+User-agent: webcopy
+User-agent: WebEnhancer
+User-agent: WebmasterWorldForumBot
+User-agent: webmirror
+User-agent: WebReaper
+User-agent: WebSauger
+User-agent: website extractor
+User-agent: Website Quester
+User-agent: Webster Pro
+User-agent: WebStripper
+User-agent: WebStripper/2.02
+User-agent: WebZip
+User-agent: wget
+User-agent: WikioFeedBot
+User-agent: WinHTTrack
+User-agent: WWW-Collector-E
+User-agent: Xenu Link Sleuth/1.3.8
+User-agent: yacy
+User-agent: yandex
+User-agent: YRSPider
+User-agent: Zeus
+User-agent: Zookabot
+Disallow: /