[FastPrep] Sync September 14 coding questions

[tomtoto757]

Summary

Synchronize the successful coding results accumulated by finalized FastPrep runs on the oldest open draft, now including five explicitly disclosed, low-confidence Google 2026 intern reconstructions.

• versus current master, the generated bank adds 88 routes, updates or refreshes 19 existing routes, and removes no route
• the latest follow-up contributes 5 verified Google coding routes, all 5 as additions
• the canonical question bank and generated Coding projection were regenerated together; pagination remains two pages
• this remains draft PR [FastPrep] Sync September 14 coding questions #188, first in the observed queue before draft PRs [FastPrep] Sync September 12 coding questions #189 and Add Google 2027 SWE Intern questions #190; no ready or merge state was changed

Generated scope

• Base: 5b447de7930e69eb88f16e15785c5c10baaea961
• Head: b8643b7e447d2f8f8a9b5dec380305d07587e19e
• Head tree: 47b8e99f4080c4fec592c1a4e83cf5030f498a60
• Complete diff: 4 files, +416/-229
• Diff SHA-256: aac4ab14beec953c6f9046aa0d294088807c296efed44804b30d52b438729f92
• Files: README.md, question-bank/page-2.md, formats/coding.md, formats/coding-page-2.md

Exact generated files:

• README.md: 399,857 bytes; blob fd383fd00743887c86b44c7305138c075fefc2b9; SHA-256 2a97f1e946b9cc675d4afb8ac154319885b55c43dfe2bbb1646305557fb1c088
• question-bank/page-2.md: 156,561 bytes; blob 7fdfd85678c6e79fd3f4d92ccf011d910897ee7f; SHA-256 7ce7101b37c4266869d81906d91f133106d486c099e7ffe807638bb2760061f0
• formats/coding.md: 399,914 bytes; blob bdf6d9bab4148c837e554c2a76836d1c524d9f41; SHA-256 d8d115594c9c922d845d90173aeb05cadfc646c388f817986c25ffcac94f52d2
• formats/coding-page-2.md: 18,217 bytes; blob f15fab52d58d9f8c98dfe067e3f28a75f9728fb0; SHA-256 75ccd2171faa33655dc8786e64e69fdfdc5393f6052fcc919beb19b10d5f4357

Latest five-route follow-up

• google-first-unique-event-in-stream
• google-stable-top-k-frequent-words
• google-run-length-encode-string
• google-reservoir-sampling-with-recorded-draws
• google-minimum-dictionary-segments

All five use the exact live FastPrep titles and Google attribution. They occur once in the canonical bank and once in the logical Coding projection, and all five public routes return HTTP 200.

Inventory and validation

• canonical inventory: 2,486 rows, 2,486 unique routes, zero route removals, and exact conservation across format projections
• format totals: Coding 2,011; SQL 36; System design 321; Low-level design 84; AI coding 34
• latest-follow-up semantic delta: exactly 5 additions, zero updates, zero removals
• complete PR semantic delta: 88 additions, 19 intended route-preserving changes, zero removals
• newest-first ordering, equal-date stability, six-pipe row shape, matching duplicate practice links, generated navigation, two-page pagination, and the 400,000-byte target / 500,000-byte hard cap passed
• TZ=UTC python3 scripts/refresh-freshness.py: passed with zero marker or ordering changes
• python3 -m unittest discover -s scripts -p 'test_*.py': 19/19 passed
• python3 scripts/sync-practice-formats.py --catalog-file <reviewed-catalog> --sync-date 2026-09-14 --check: passed
• git diff --check: passed
• only the four generated Markdown targets changed; no credentials or source-only material are present

Independent regression review

• reviewed head: b8643b7e447d2f8f8a9b5dec380305d07587e19e
• reviewed base: 5b447de7930e69eb88f16e15785c5c10baaea961
• result: PASS; no remaining P0-P2 findings
• resolved findings: corrected four touched titles to the exact live FastPrep catalog values and refreshed this PR body
• scope: complete four-file diff, 2,486-route canonical bank, 88-add/19-change aggregate delta, five-route follow-up, route uniqueness and conservation, metadata parity, ordering, pagination, size limits, public HTTP availability, sensitive-data scan, and generator tests
• automated PR checks: none attached; confidence is based on the recorded deterministic local validations and exact-head independent review

Queue state

The open master queue observed for this run is draft PR #188 followed by separate draft PRs #189 and #190. All three were CLEAN with no attached checks at the recorded observation. The current request does not explicitly authorize making any PR ready or merging it, so no queue merge mutation was attempted.

Remaining risks

• the repository contains nine inherited catalog-missing coding rows unrelated to this batch; this update neither introduces nor removes them
• production catalog and GitHub observations are point-in-time evidence and can drift after the recorded review
• readying or merging the ordered draft queue still requires explicit authorization