Feat/state machine callbacks

[Elan456]

Description

Adds methods to the BaseStateMachine to allow for registering function to be called on state entry.

Summary of Changes

• BaseStateMachine stores an array of function ptrs for callbacks
• Add registerOnStateEntry to add new functions for callbacks
• Add a changeState method which should now always be used to change states in a state machine because it will check and call the callbacks.
• Make the state_ variable private, so that you cannot change it unless you use the changeState method.

Motivation

• See StateMachine Callbacks #81

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Testing

Check all that apply:

• I have added or modified unit tests to cover these changes.
• I have manually tested the changes on the target device(s) or environment(s).
• Existing tests were reviewed to ensure they still work as expected.
• If tests were not added or modified, explain why:

  (Provide reasoning here)

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Checklist

• My code follows the style guidelines of this project.
• I have performed a self-review of my own code.
• I have commented my code where necessary for clarity.
• I have made corresponding updates to documentation (if applicable).

[Copilot]

Pull request overview

I read the AGENTS.md.

Adds shared state ownership and state-entry callback dispatch to the state machine framework, so external components can register hooks that run when a flight state is entered.

Changes:

• Introduces BaseStateMachine state tracking plus fixed-capacity state-entry callback registration/dispatch.
• Updates StateMachine and BurnoutStateMachine to transition via changeState() and read state via getFlightState().
• Makes FlightState explicitly uint8_t with fixed numeric values and updates state-estimation README notes.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/state_estimation/StateMachine.cpp	Uses BaseStateMachine state storage and changeState() transitions.
src/state_estimation/BurnoutStateMachine.cpp	Migrates transitions/state reads to the new base functionality.
src/state_estimation/BaseStateMachine.cpp	Implements callback registration and dispatch on state transitions.
include/state_estimation/States.h	Makes FlightState an explicit uint8_t enum with fixed values.
include/state_estimation/StateMachine.h	Removes local state_ storage and getState() override.
include/state_estimation/BurnoutStateMachine.h	Removes local state_ storage and getState() override.
include/state_estimation/BaseStateMachine.h	Defines the callback API, fixed-capacity storage, and state encapsulation.
include/state_estimation/README.md	Updates documentation to reflect callback support and capacity/no-allocation design.

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 2 comments.

[Jshepherd06]

Looks good to me