Block coordinate traffic on configured event channels (#11045)

* Block coordinate traffic on configured event channels

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

* Suppress event coordinates in reliable relay paths

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

* Reject blocked phone coordinates before rate limiting

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

* Prevent event coordinates from reaching MQTT

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

* Add event coordinate policy preference

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

* Test event coordinate policy in native CI

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

* Make event policy test tolerate a full NodeDB

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

* Test Router event coordinate enforcement

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

* Test PhoneAPI event coordinate retry handling

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

* Test reliable event coordinate suppression

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

* Test MQTT event coordinate suppression

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

* Run event policy behavioral suites in native CI

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

* tests: address CodeRabbit review feedback

- test_event_channel_phone_api: complete the setUp/tearDown save-restore
  pair. GlobalState now carries cryptLock and myNodeInfo; setUp() nulls
  cryptLock before constructing MockRouter (Router's ctor asserts it is
  unset), and tearDown() restores both so the suite leaves no global
  mutated. Not reachable today - the globals start null in this binary -
  but the pair was asymmetric.

- Replace the strcpy calls this branch added on Channel.settings.name
  (char[12]) with the bounded form the rest of the test tree already uses,
  strncpy(dst, src, sizeof(dst) - 1). Covers the flagged site in
  test_nexthop_routing plus the six equivalents in
  test_event_channel_phone_api, test_mqtt and test_position_precision,
  which trip the same ast-grep dangerous-buffer-functions-cpp rule.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

---------

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
Co-authored-by: Ben Meadors <benmmeadors@gmail.com>
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

src/mesh/PositionPrecision.cpp

@@ -16,6 +16,10 @@ uint32_t getPositionPrecisionForChannel(const meshtastic_Channel &channel)
 
 uint32_t getPositionPrecisionForChannel(uint8_t channelIndex)
 {
+    // Event-channel privacy takes precedence over every stored precision and key policy.
+    if (channels.isEventChannel(channelIndex))
+        return 0;
+
     const meshtastic_Channel &ch = channels.getByIndex(channelIndex);
     if (ch.role == meshtastic_Channel_Role_DISABLED)
         return 0;