1.9.2 review notes

Review boundary

This change implements only the active 1.9.2 beginner-learning-path milestone. It adds documentation, runnable examples, output/search checks, and an automated clean-archive beginner-journey gate. It does not change any declaration in the frozen public 1.9 API snapshot and does not begin 1.9.3 API-decision or later trust, performance, portability, migration, beta, or freeze work.

Reviewable changes

1. Put the double-real, simple allocating route before generic implementation details and expert destination/workspace controls. 2. Give every stable domain a beginner route, common-task choice, exact contract/failure links, allocation/precision note, and tested advanced example. 3. Add a newcomer guide for arrays, zero-based indexing, interface lifetimes, callbacks, options, statuses, exceptions, copies, and precision. 4. Add task recipes for all families named by the 1.9.2 roadmap and make the common-problem search phrases mechanical checks. 5. Qualify first use mechanically from a checksummed clean archive: verify problem-oriented search, all beginner and advanced links, compile/run every beginner program, compare claimed output, and audit public declarations.

Compatibility evidence

tools/test_api_snapshot.py and tools/check_docs.py continue to compare all source interface sections with the unchanged 1.9.0 snapshot. The change adds no public type, algorithm family, convenience overload, default, deprecation, storage rule, or implicit conversion.

Completion-gate status

Every 1.9.2 gate is deterministic and can run from a clean archive without external participation, accounts, reports, services, or network access. The release driver checks documentation structure and declarations, compiles and runs all published beginner programs, compares claimed output, builds the searchable versioned site, checks problem phrases and links, and verifies the offline archive before qualification can pass.