refactor(b20-asset, activation): remove unreachable announcement guard and redundant AlreadyDeactivated error

[rayyan224]

Summary

B20 Asset — announcement guard (BOP-292 finding #1)

• Removes the in_announcement: bool field, is_announcement_active(), and begin_announcement() from B20AssetToken
• Removes the dead is_announcement_active() guard and begin_announcement() call from announce() in dispatch.rs
• Corrects the announce doc comment to name the selector check as the sole recursion defense

Activation Registry — redundant error (BOP-292 finding #2)

• Removes AlreadyDeactivated from activation/abi.rs — it was declared but never returned
• Clarifies set_activated variable names to make the activate/deactivate branch intent explicit

Context

Finding #1 — unreachable is_announcement_active() guard

The is_announcement_active() check in announce() was structurally unreachable:

1. begin_announcement() was called after the check, so in_announcement was always false when the guard ran.
2. The only re-entry vector — the inner call loop — already rejects the announce selector before dispatch, so a recursive call could never reach the outer function body where the guard lives.
3. There was no end_announcement() or reset, leaving the token permanently stuck with in_announcement = true after announce() completed — a one-way latch with no observable effect only because the token is constructed fresh per invocation.

Cross-checked against MockB20Asset.sol: the reference implementation carries no flag at all. Its two actual defenses are the selector check (_checkSelector) and early ID marking before inner calls run. The Rust now matches this exactly.

Finding #2 — redundant AlreadyDeactivated error

AlreadyDeactivated and FeatureNotActivated both represent the same underlying state — features[feature] == false. The intended distinction (mutation context vs query context) was never implemented: MockActivationRegistry.sol collapses both into FeatureNotActivated. AlreadyDeactivated was not just unused — it was redundant with an existing error. Removed from the Rust ABI to match the updated IActivationRegistry spec.

Test plan

• cargo test --manifest-path crates/common/precompiles/Cargo.toml — all 344 tests pass
• No remaining references to is_announcement_active, begin_announcement, in_announcement, or AlreadyDeactivated in the crate tree

[linear]

BOP-292

[cb-heimdall]

🟡 Heimdall Review Status

Requirement	Status	More Info
Reviews	🟡 0/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 0 Sum 1

[rayyan224]

This is not logic change, making it more readable with clean code principles

[github-actions]

== true / == false comparisons on bool values will trigger clippy::bool_comparison (enabled via clippy::all in the workspace). Idiomatic Rust:

Suggested change

	let is_activating_and_already_activated =
	to_activated_state == true && current_activated_state == true;
	let is_deactivating_and_already_deactivated =
	to_activated_state == false && current_activated_state == false;
	let is_activating_and_already_activated =
	to_activated_state && current_activated_state;
	let is_deactivating_and_already_deactivated =
	!to_activated_state && !current_activated_state;

[rayyan224]

Keeping it verbose is a stylstic descion

[github-actions]

Review Summary

Clean removal of dead code — the analysis in the PR description is thorough and the changes are correct. No remaining references to the removed items (is_announcement_active, begin_announcement, in_announcement, AlreadyDeactivated) exist anywhere in the crate tree.

Finding

activation/storage.rs:137-140 — clippy::bool_comparison: The new == true / == false comparisons on bool values are non-idiomatic and will be flagged by clippy::bool_comparison (enabled via clippy::all in the workspace lints). See inline comment for suggested fix.

[github-actions]

✅ base-std fork tests: all 602 passed

base/base is fully in sync with the base-std spec.