feat: add adapter detection via config file content

[HarshMN2345]

Summary

• Adds getConfigFiles() and getAdapter() methods to the Framework base class
• Implements adapter detection for dual-adapter frameworks: TanStack Start, SvelteKit, Astro, Remix
• Each framework reads its config file and detects whether the project is configured for SSR or static output

Detection logic

Framework	Config file(s)	Static signal	Default
TanStack Start	vite.config.ts/js/mjs	prerender keyword	ssr
SvelteKit	svelte.config.js/ts or package.json	@sveltejs/adapter-static	ssr
Astro	astro.config.mjs/js/ts	output: 'server' or 'hybrid'	static
Remix	package.json	always ssr (static is edge case)	ssr

Test plan

• Verify detection returns correct adapter for SSR and static variants of each framework
• Verify fallback to empty string works when no config file is present

[greptile-apps]

Greptile Summary

• Adds base framework APIs for listing adapter config files and detecting SSR/static adapters from config content.
• Implements adapter detection for Astro, Remix, SvelteKit, and TanStack Start.
• Adds unit tests covering adapter detection behavior and config edge cases.

Confidence Score: 5/5

The changes are narrowly scoped to framework adapter detection and accompanying unit coverage.

No code issues were identified in the reviewed changes, and the implementation is covered by targeted tests for the new detection behavior.

T-Rex Logs

What T-Rex did

• Baseline checks confirmed that the base commit’s framework classes do not implement getConfigFiles or getAdapter, which explains the METHOD_ABSENT observations in the initial run.
• The head commit introduces getConfigFiles and getAdapter on the framework classes and yields the expected config files and adapter values across all checked scenarios.
• The React fallback case is verified to produce an empty configFiles array and an empty adapter string as part of the head-commit behavior.

_{Ran code and verified through T-Rex}

_{Reviews (6): Last reviewed commit: "fix: handle quoted prerender key in TanS..." | Re-trigger Greptile}