CHORE: Update org references from slatekit to kiitdev

[kishorereddy]

Overview

Updates every reference to the old slatekit GitHub org to kiitdev, and trims the long file
header down to a single line, now that the org rename to match the kiit.dev domain is live.

Ticket(s)

N/A

Links(s)

N/A

Example(s)

• README.md's badges and Issues link now point at github.com/kiitdev/kiit-codes.
• Every source file's header shrinks from the old multi-line <kiit_header> block down to
  /** url: www.kiit.dev */.

Dependencies

Depends on the GitHub org itself already being renamed from slatekit to kiitdev (done).

Design

1. Org references: README.md's CI badge, license badge, and Issues link, plus
   kiit-codes/build.gradle.kts's scm block (url/connection/developerConnection), all
   updated from slatekit to kiitdev. These were deliberately left unchanged in an earlier PR
   since they'd have broken before the org rename actually happened.
2. File headers: replaced the old boilerplate header (url, git, org, author, copyright,
   license, about) with a single line, /** url: www.kiit.dev */, across every source file that
   had it.

Notes

Verified with a repo-wide, case-insensitive search that no slatekit or old-header references
remain anywhere in the codebase.

Pending

None.

Tests

None, no behavioral change, comments and metadata only.