feat(elections): add adaptive staking strategy

[Keshoid]

Summary

• Add AdaptiveSplit50 staking strategy that adapts stake amount based on current election state
• Emulate TON Elector's selection algorithm to compute minimum effective stake
• Split funds in half when viable, stake everything when half is below threshold
• Top-up stake when competitors raise theirs

Changes

• election_emulator.rs — new module: emulates Elector's try_elect + compute_min_effective_stake
• adaptive_strategy.rs — new module: is_adaptive_split50_ready (wait/sleep logic) + calc_adaptive_stake
• runner.rs — integrate adaptive strategy into election runner, filter own stake from participants
• app_config.rs — add sleep_period_pct, waiting_period_pct config fields
• staking-strategies.md — documentation for the strategy
• Unit + integration tests covering emulation, stake calculation, and 3-tick top-up cycle

Closes SMA-35

[linear]

SMA-35 Add adaptive staking strategy

[Copilot]

Copilot reviewed 13 out of 13 changed files in this pull request and generated 2 comments.

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[Copilot]

Configuration parameter validation only applies when the full ElectionsConfig is validated, but sleep_period_pct and waiting_period_pct are added to the config regardless of the selected stake policy. These parameters should only be required/validated when AdaptiveSplit50 strategy is in use. Consider documenting this design choice or conditionally validating these parameters only for AdaptiveSplit50 policy.

Suggested change

	if !(0.0..=1.0).contains(&self.sleep_period_pct) {
	anyhow::bail!("sleep_period_pct must be in range [0.0..1.0]");
	}
	if !(0.0..=1.0).contains(&self.waiting_period_pct) {
	anyhow::bail!("waiting_period_pct must be in range [0.0..1.0]");
	}
	if self.sleep_period_pct > self.waiting_period_pct {
	anyhow::bail!("sleep_period_pct must be <= waiting_period_pct");
	}
	// `sleep_period_pct` and `waiting_period_pct` are only relevant for the
	// AdaptiveSplit50 stake policy. We only validate them if that policy is
	// used either as the default or in any per-node override.
	let uses_adaptive_split50 = matches!(self.policy, StakePolicy::AdaptiveSplit50 { .. })
	|| self
	.policy_overrides
	.values()
	.any(|policy| matches!(policy, StakePolicy::AdaptiveSplit50 { .. }));
	if uses_adaptive_split50 {
	if !(0.0..=1.0).contains(&self.sleep_period_pct) {
	anyhow::bail!("sleep_period_pct must be in range [0.0..1.0]");
	}
	if !(0.0..=1.0).contains(&self.waiting_period_pct) {
	anyhow::bail!("waiting_period_pct must be in range [0.0..1.0]");
	}
	if self.sleep_period_pct > self.waiting_period_pct {
	anyhow::bail!("sleep_period_pct must be <= waiting_period_pct");
	}
	}

[Keshoid]

Skipped. Validating always is simpler and catches misconfigs early.

[Copilot]

The MIN_NANOTON_FOR_STORAGE constant was increased from 1_000_000_000 to 1_050_000_000 nanotons (1.0 to 1.05 TON). While the increase improves safety margins, the rationale for this specific increase should be documented in the code comment to explain why 1.05 TON was chosen.

Suggested change

	/// Reserved minimum balance on the wallet (or pool) balance for stake calculations
	/// Reserved minimum balance on the wallet (or pool) balance for stake calculations.
	/// 1.05 TON (1_050_000_000 nanotons) is used instead of 1.0 TON to include a safety
	/// margin that covers storage rent and small gas/fee fluctuations, reducing the risk
	/// that stake or recovery operations fail due to the wallet balance dropping too close
	/// to the protocol's minimal storage requirements.

[Keshoid]

Added a descriptive comment.

[mrnkslv]

for me it's hard to read this comment. Should i use some special extension for ide?)(e.g. /// ```text - shoud it has formatting in comments?)