[codex] Add canonical app catalog support

[n30nex]

Summary

• Align firmware catalog validation with the canonical limitlezz.app.catalog.v1 contract used by docs, examples, and the Python validator.
• Add typed cached catalog loading and render cached network catalog rows in App Store browsing/update metadata instead of the old static LZ_STORE examples.
• Tighten catalog docs/validator bounds for safe IDs, HTTPS package URLs, lowercase SHA256, package size, compatibility, permissions, and screenshots.
• Fix the T-Deck smoke wrapper's esptool argument spelling so fetched artifacts can be flashed through the scripted COM8 workflow.

Validation

• git diff --check
• python scripts\validate_app_catalog.py docs\examples\app-catalog-index.json
• python -m py_compile scripts\validate_app_catalog.py scripts\fetch_tdeck_artifact.py scripts\release_evidence.py scripts\tdeck_smoke.py scripts\serial_harness.py
• python scripts\validate_local_app_samples.py
• pio run -e native
• .\.pio\build\native\program.exe --selftest
• .\.pio\build\native\program.exe --simtest
• pio run -e tdeck

CI / Artifact

• Firmware CI run: 27875548938
• Commit: 5f4b5231801a78b7d8113ae4f8cadb2c62247878
• Artifact: tdeck-firmware-5f4b5231801a78b7d8113ae4f8cadb2c62247878
• Size budget: pass; firmware_bytes=1579136, firmware_slot_pct=30.12, static_ram_bytes=229908

Hardware

• Fetched exact artifact with scripts\fetch_tdeck_artifact.py into .pio\ci-artifacts\tdeck-app-catalog-canonical-5f4b523.
• Flashed COM8 only using scripts\tdeck_smoke.py --port COM8 --no-stub-upload --skip-build --artifact-dir .pio\ci-artifacts\tdeck-app-catalog-canonical-5f4b523.
• Flash target was ESP32-S3 rev v0.2, MAC cc:8d:a2:0d:14:28; bootloader, partitions, boot_app0, and firmware hashes verified.
• First serial pass reached id then timed out on sys; no-reflash retry passed with id, sys, app catalog test, and app catalog status.
• Observed app catalog test: App catalog selftest: PASS valid=2 invalid_error="bad package_sha256".
• Observed app catalog status: app catalog: no cached index.