[RTY-260011] : Cache implementation

[harshmishra2701]

…TTL and documentation"

Pull Request Template

Description

This PR introduces an in-memory caching layer to speed up short URL resolution and reduce repeated database lookups. The cache stores both short_code → original_url and original_url → short_code mappings with a TTL of 15 minutes. This helps handle frequent requests efficiently (e.g., repeated access to the same 5 URLs within a short time window).

Fixes #11

Type of change

• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

How Has This Been Tested?

• Verified that repeated requests for the same short URLs are served from cache within the TTL window.
• Verified cache expiry after 15 minutes results in fallback to DB fetch.
• Ran the application locally and confirmed URL creation and redirection work as expected with caching enabled.

Test Configuration:

• Browser: Chrome
• Device: laptop

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings
  📸 Additional context (Screenshots / Evidence)

[recursivezero]

getting error when run poetry run tiny api and execute shorten POST API

AttributeError: module 'app.utils.data' has no attribute 'urls'