Devnet integration docs (#3762)

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Closes #3603 

**Stack**:
- #3762 ⬅
- #3761
- #3760

## Checklist

<!-- Make sure all of these are complete -->

- [x] Linked relevant issue
- [x] Updated relevant documentation
- [ ] Added relevant tests
- [x] Performed self-review of the code
- [x] Added changes to `CHANGELOG.md`

---------

Co-authored-by: Artur Michalek <[email protected]>
Co-authored-by: Artur Michałek <[email protected]>

Author: franciszekjob

CHANGELOG.md

@@ -19,6 +19,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Debug logging for `sncast` commands that can be enabled by setting `CAST_LOG` env variable.
 - `sncast declare` command now outputs a ready-to-use deployment command after successful declaration.
+- Possibility to use [`starknet-devnet`](https://github.com/0xSpaceShard/starknet-devnet) predeployed accounts directly in `sncast` without needing to import them. They are available under specific names - `devnet-1`, `devnet-2`, ..., `devnet-<N>`. Read more [here](https://foundry-rs.github.io/starknet-foundry/starknet/integration_with_devnet.html#predeployed-accounts)
 
 ## [0.50.0] - 2025-09-29
 

docs/src/SUMMARY.md

@@ -59,6 +59,7 @@
 * [Verifying Contracts](starknet/verify.md)
 * [Calldata Transformation](starknet/calldata-transformation.md)
 * [Block Explorers](starknet/block_explorer.md)
+* [Integration With Devnet](starknet/integration_with_devnet.md)
 * [Developer Functionalites](starknet/developer.md)
 
 ---

docs/src/starknet/integration_with_devnet.md

@@ -0,0 +1,42 @@
+# Integration With Devnet
+
+[`starknet-devnet`](https://0xspaceshard.github.io/starknet-devnet/) is a local Starknet node used for development and testing. `sncast` provides inbuilt support for some of its features, making it easier to work with it.
+
+## Predeployed Accounts
+
+When you start `starknet-devnet`, it automatically predeploys some contracts, including set of accounts with known details (read more about them [here](https://0xspaceshard.github.io/starknet-devnet/docs/predeployed)).
+
+You can use these accounts directly in `sncast` without needing to import them. 
+They are available under specific names - `devnet-1`, `devnet-2`, ..., `devnet-<N>` (where N is the number of predeployed accounts, by default it's 10). 
+
+> 📝 **Note**
+>
+> Devnet accounts can't be used together with `sepolia` and `mainnet` values for `--network` flag.
+
+
+### Example
+
+Let's invoke a contract using `devnet-1` account.
+
+```shell
+$ sncast --account devnet-1 invoke \
+  --contract-address 0x0589a8b8bf819b7820cb699ea1f6c409bc012c9b9160106ddc3dacd6a89653cf \
+  --function "get_balance"
+```
+
+<details>
+<summary>Output:</summary>
+
+```shell
+Success: Invoke completed
+
+Transaction Hash: [..]
+
+To see invocation details, visit:
+transaction: https://sepolia.starkscan.co/tx/[..]
+```
+</details>
+
+> 📝 **Note**
+>
+> If you have an account named `devnet-1` (or any other predeployed account name) in your accounts file, `sncast` will prioritize using that one instead of the inbuilt devnet account.