Recover PR #202 UK source facts onto main

[juaristi22]

Summary

PR #202 was merged into chronicle-196-uk-targets after that branch's PR had already merged, so its reviewed source additions never reached main. This PR recovers the final reviewed #202 tree onto current main.

It includes:

• DfC Northern Ireland Universal Credit statistics from the May 2026 release, including both 2025 and 2026 facts; the superseded duplicate May 2025 bundle remains removed
• ONS PIPR local-rent facts for all available years from 2023 through 2026
• DfT BUS0415 fares index, BUS05i revenue/support, and NTS0705 local-bus-trip facts
• HMRC Capital Gains Tax facts by age, country/region, and gain-by-income band
• the reviewed DWP vocabulary and Scottish council-tax source fixes associated with UC concept rename and scotgov measure-id collision silently deactivate 19 national targets #203
• current-main DFE/TFC source registration introduced after the original branch diverged

This keeps Chronicle source-only: it does not restore target profiles, which belong in the Microcosm consumer.

Verification

• All reviewed source/package paths match Add 2023-2026 UK facts and restore source vocabulary #202's final reviewed head (0ffa3ea) byte-for-byte
• Full test suite: 746 passed, 1 skipped
• Ruff: passed
• git diff --check: passed
• Combined bundle: 188,614 facts, 160 source packages, 45 sources

Recovery of #202. Includes the source compatibility work discussed in #203.