Add IN_433 regulatory region

[kholia]

Configure India 433 MHz operation for 433.05-434.79 MHz at 10 dBm with a 10% duty-cycle limit, as specified by G.S.R. 347(E), 2022.

PDF reference of the G.S.R.

Add region lookup coverage and update the client compatibility snapshot.

Note: Depends on meshtastic/protobufs#998.

On why we need a different region configuration:

   Existing region    Why it cannot represent India safely
  ━━━━━━━━━━━━━━━━━  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
   ANZ_433            Same frequency range, but permits 14 dBm and 100% duty cycle.
  ─────────────────  ───────────────────────────────────────────────────────────────────────────────
   UA_433             Same 10 dBm/10%, but starts at 433.00 MHz—below India’s 433.05 MHz boundary.
  ─────────────────  ───────────────────────────────────────────────────────────────────────────────
   EU_433             Also starts below the Indian boundary and stops at 434.00 MHz.
  ─────────────────  ───────────────────────────────────────────────────────────────────────────────
   KZ_433             Frequency is a legal subset and power is 10 dBm, but permits 100% duty cycle.

🤝 Attestations

• I have tested that my proposed changes behave as described.
• I have tested that my proposed changes do not cause any obvious regressions on the following devices:
  • Heltec (Lora32) V3
  • LilyGo T-Deck
  • LilyGo T-Beam
  • RAK WisBlock 4631
  • Seeed Studio T-1000E tracker card
  • Other (please specify below)

Summary by CodeRabbit

• New Features

  • Added support for the India 433 MHz LoRa region (IN_433), including its applicable frequency range, duty-cycle, and power limits.
  • Updated region-to-preset compatibility information to include IN_433 in the default region group.

• Documentation

  • Updated the compatibility specification and reference tables to reflect the new regional option.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro Plus

Run ID: 0d28b406-0203-44e3-8b1d-024116b493e3

📥 Commits

Reviewing files that changed from the base of the PR and between dafa583 and b1510db.

📒 Files selected for processing (3)

• docs/lora_region_preset_compatibility_client_spec.md
• src/mesh/RadioInterface.cpp
• test/test_admin_radio/test_main.cpp

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📝 Walkthrough

Walkthrough

Adds the IN_433 LoRa region with its regulatory parameters, updates region-group compatibility documentation, and adds unit-test coverage for region lookup.

Changes

IN_433 region support

Layer / File(s)	Summary
Compatibility metadata docs/lora_region_preset_compatibility_client_spec.md	Updates the nanopb receive count from 38 to 39 and adds IN_433 to group 0.
Region registration src/mesh/RadioInterface.cpp	Adds IN_433 with its 433.05–434.79 MHz range and regulatory limits.
Region lookup validation test/test_admin_radio/test_main.cpp	Tests IN_433 metadata and registers the test with the Unity runner.

Estimated code review effort: 2 (Simple) | ~10 minutes

Possibly related PRs

• meshtastic/firmware#11009: Adds another LoRa regulatory region to the same region table.

Suggested labels: enhancement, requires-protos

Suggested reviewers: thebentern, caveman99

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title is concise and accurately highlights the main change: adding the IN_433 regulatory region.
Description check	✅ Passed	The description covers the change, rationale, dependency, and includes the required attestations section.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[caveman99]

This will be covered by EU_433 from version 3.0 - see #2696 - up to that point you need to use EU_433