safety: make demo and nearby dispatch claims honest

[NITISH-R-G]

Description

Hardens RoadSOS emergency truthfulness after a critical feature audit:

• Demo Mode now uses a separate simulated orchestrator path instead of calling the live SOS pipeline.
• Demo dispatch rows are marked skipped for SMS, BLE, local log, Family Circle, and nearby services, with explicit no-dispatch copy.
• nearby_services no longer reports fake success from a delayed timer; it is marked skipped/manual-action-only until a real responder/facility broadcast exists.
• README now includes a Functional Reality Check and downgrades BLE mesh/encryption and dispatch claims to match current implementation.
• Added regression guards for demo/nearby false-success behavior.

Fixes # N/A

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

How Has This Been Tested?

• Unit Tests (source-level regression guard added; full Flutter runner unavailable in this cloud image)
• Integration Tests
• Manual Smoke Test (on physical device)

Commands/checks run:

• python3 source safety assertions for removal of fake nearby success and live demo call
• git diff --check
• Attempted dart format ... -> blocked: dart: command not found
• Attempted flutter test test/orchestrator_test.dart -> blocked: flutter: command not found
• RoadSOS critical reviewer subagent: no blocking issues found; noted human two-reviewer process for orchestrator changes

Checklist:

• My code follows the style guidelines of this project (manual review; formatter unavailable)
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings (no SDK available to run analyzer)
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes