chore: remove workspace, change to single package repo

[arad-starkware]

This change is 

---

Note

Converts the repo from a workspace to a single Scarb package and updates CI/codecov paths and the flow-test checker accordingly.

• Build/Config:
  • Replace workspace Scarb.toml with single-package config in root ([package], [dependencies], [dev-dependencies], [[target.starknet-contract]], tests, features, fmt, profiles).
  • Remove workspace/apps/staking/contracts/Scarb.toml.
• CI:
  • Update Codecov path from workspace/apps/staking/contracts/coverage/coverage.lcov to coverage/coverage.lcov in .github/workflows/on-pull-request.yaml.
• Scripts:
  • Adjust scripts/check_all_flows_have_test.py to use repo root as CONTRACTS_FOLDER instead of workspace/apps/staking/contracts.

^{Written by Cursor Bugbot for commit fad9926. This will update automatically on new commits. Configure here.}

[arad-starkware]

• chore: remove workspace, change to single package repo #25 👈 (View in Graphite)
• ci: add PR CI #24
• main

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
⚠️ Please upload report for BASE (main@0d4c1ff). Learn more about missing BASE report.

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #25   +/-   ##
=======================================
  Coverage        ?   95.38%           
=======================================
  Files           ?       45           
  Lines           ?     9337           
  Branches        ?        0           
=======================================
  Hits            ?     8906           
  Misses          ?      431           
  Partials        ?        0           

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