doc: Fix fast-runtime documentation (#311)

`fast-runtime` features does not shortens block time to 3 s. It keeps it at 6 s and instead shortens epochs (1‑minute) and eras (3 sessions) to speed up validator churn and testing workflows.

README.md

@@ -271,7 +271,7 @@ See `.github/workflows/` for workflow definitions.
 - **Type mismatches**: Regenerate with `bun generate:types` after runtime changes
 - **Contract changes not reflected**: Run `bun generate:wagmi` after modifications
 - **Kurtosis issues**: Ensure Docker is running and Kurtosis engine is started
-- **Slow development**: Use `--features fast-runtime` for faster block times
+- **Slow development**: Use `--features fast-runtime` for shorter epochs/eras (block time stays 6s)
 - **Network launch hangs**: Check Blockscout - forge output can appear frozen
 
 See [CLAUDE.md](./CLAUDE.md) for detailed development guidance.

operator/README.md

@@ -45,13 +45,13 @@ operator/
 
 ### Development Build (Fast Runtime)
 
-For local development with faster block times:
+For local development with shorter epochs and eras:
 
 ```bash
 cargo build --release --features fast-runtime
 ```
 
-This enables 3-second block times instead of the production 12-second blocks.
+This switches runtime parameters to the fast variants (1-minute epochs, 3 sessions per era) while the block time remains 6 seconds.
 
 ### Production Build
 

test/README.md

@@ -68,7 +68,7 @@ The `bun cli launch` command deploys a complete local environment:
 2. **DataHaven Network**:
    - Single validator solochain
    - EVM compatibility via Frontier
-   - Fast block times (3s with `--fast-runtime`)
+   - Fast churn settings (`--fast-runtime` gives 1-minute epochs and 3-session eras while block time stays 6s)
 
 3. **Smart Contracts**:
    - EigenLayer AVS contracts deployed to Ethereum