Refactor serializer in Serviceability

[juan-malbeclabs]

This pull request makes significant improvements to the Solana program's structure, documentation, and code quality. The most important changes are the addition of comprehensive instruction implementation guidelines, major refactoring and removal of legacy account management code, and the consolidation of account serialization/creation logic into a new serializer module. Several processors and helpers are updated to use the new serialization helpers, and some redundant modules are removed for clarity.

Documentation and Guidelines:

• Added a detailed INSTRUCTION_GUIDELINES.md file to document best practices and required steps for implementing new instructions, including account parsing, validation, state mutation, error handling, and a checklist.

Codebase Refactoring and Cleanup:

Account Management and Serialization:

• Removed legacy account management functions from accounts.rs and helper.rs, such as account creation, writing, and closing logic, in favor of new, consolidated helpers. [1] [2]
• Introduced a new serializer module for account serialization, writing, and closing, and updated relevant processors (e.g., access pass) to use these new helpers. [1] [2] [3] [4] [5]

Module and Import Organization:

• Simplified and reorganized module imports in lib.rs, removing unused or redundant modules and ensuring only necessary modules are public.
• Removed the unused doublezero_foundation address module for clarity.

Global State Management:

• Removed legacy global state read/write and reallocation logic from globalstate.rs, streamlining state management to rely on new helpers.

These changes collectively improve maintainability, enforce best practices, and modernize the codebase for future development.

Testing Verification

• All tests were executed and no errors occurred.

[Copilot]

Pull request overview

This pull request refactors the Solana program to consolidate account serialization and management logic. The primary focus is removing legacy helper functions and introducing a new serializer module with standardized helpers (try_acc_create, try_acc_write, try_acc_close) for account operations. Additionally, comprehensive instruction implementation guidelines are added, and unused code is removed to improve maintainability.

• Introduced a new serializer module with unified account creation, writing, and closing helpers
• Removed legacy AccountTypeInfo trait implementations and replaced size() calls with borsh::object_length()
• Added INSTRUCTION_GUIDELINES.md documenting best practices for implementing new instructions

Reviewed changes

Copilot reviewed 106 out of 107 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
src/serializer.rs	New module providing try_acc_create, try_acc_write, and try_acc_close helper functions
src/helper.rs	Removed legacy account management functions, retained BGP community assignment
src/accounts.rs	Deleted entire file containing deprecated account management traits and functions
src/globalstate.rs	Removed globalstate_write and reallocation helpers, kept only minimal read logic
src/state/*.rs	Removed AccountTypeInfo implementations and try_serialize methods from state structs
src/processors/**/*.rs	Updated all processors to use new serializer helpers instead of legacy functions
tests/*.rs	Updated tests to use borsh::object_length() instead of .size() method
INSTRUCTION_GUIDELINES.md	Added comprehensive documentation for instruction implementation patterns

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