chore(docs): remove non-e2e documentation

docs/credentials.md

@@ -1,64 +0,0 @@
-# Credentials & LLM Providers
-
-## Setup
-
-```bash
-multica credentials init
-```
-
-Creates:
-- `~/.super-multica/credentials.json5` — LLM providers + tools
-
-Example `credentials.json5`:
-
-```json5
-{
-  version: 1,
-  llm: {
-    provider: "openai",
-    providers: {
-      openai: { apiKey: "sk-xxx", model: "gpt-4o" }
-    }
-  },
-  tools: {
-    brave: { apiKey: "brv-..." }
-  }
-}
-```
-
-## Skill API Keys
-
-Skill-specific API keys are stored in `.env` files within each skill's directory:
-
-```
-~/.super-multica/skills/<skill-id>/.env
-```
-
-Example for the `earnings-analysis` skill:
-
-```bash
-# ~/.super-multica/skills/earnings-analysis/.env
-FINANCIAL_DATASETS_API_KEY=your-key-here
-```
-
-Skills declare their required environment variables in `SKILL.md` frontmatter:
-
-```yaml
-metadata:
-  requires:
-    env:
-      - FINANCIAL_DATASETS_API_KEY
-```
-
-The `.env` file is preserved across skill upgrades and is never committed to version control.
-
-## LLM Providers
-
-**OAuth Providers** (external CLI login):
-- `claude-code` — requires `claude login`
-- `openai-codex` — requires `codex login`
-
-**API Key Providers** (configure in `credentials.json5`):
-- `anthropic`, `openai`, `kimi-coding`, `google`, `groq`, `mistral`, `xai`, `openrouter`
-
-Check status: `/provider` in interactive mode