docs: build source-aligned PTO specification portal

[zhoubot]

Summary

• migrate all 634 released mnemonic routes across 850 ASL units to one Arm-style, source-aligned workbench
• add canonical instruction and NDF indexes, persistent locale-aware navigation, URL-driven instruction facets, and complete NDF detail relationships
• derive high-level Tile assembly from structured ASL-owned bundle metadata and fail closed on prose-shaped B.DIM forms
• embed exact ASL, NDF, ADR/Decision, and AVS content with source identities, accessible semantic IDs, and progressive disclosure
• reconcile the portal with PR Define CELL rearrangement vector operations #161: 107 current Tile owners, singleton complete-parent Shared semantics, retired owners removed, and ADR-0103 bound to the squash landing parent

Architecture boundary

The portal remains a generated view over owning ASL/NDF sources. The four TCONCAT/TEXTRACT/TINSERT/TMOV ASL edits only normalize B.DIM metadata from prose into explicit optional LB1/LB2 entries; they do not change instruction semantics. The ADR-0103 edit repairs the baseline identity invalidated by PR #161 squash landing. Generated documentation and commit-scoped evidence are refreshed from those owners.

Local evidence

• make pr-check
• make repo-check
• make site-check
• make site-e2e: 52 passed, 2 skipped
• make site-quality: desktop performance 100, mobile performance 97, accessibility 99-100, best practices 96, SEO 100, CLS 0
• Docusaurus English and zh-CN build
• site artifact: 850 bilingual unit routes, 634 bilingual instruction rows, 0 unexplained omissions
• git diff --check

Scope exclusions

This PR does not publish the site, run release preparation, create a tag or GitHub Release, deploy Pages, or merge itself.