[Frontend] Implement Centralized Toast/Notification System for Error and Success Messages

[devJaja]

🎯 Objective

Add configurable storage size limits per agent to prevent unbounded persistent storage growth in the agent_registry Soroban contract.

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📁 Files to Modify

Action	File Path	Description
Modify	smart-contracts/contracts/agent_registry/src/lib.rs	Add max agent count, per-capability limits, and total_agents() read function

📁 Reference Files

File Path	Purpose
smart-contracts/contracts/agent_registry/src/lib.rs (line ~183)	append_capability_index — unbounded Vec growth
smart-contracts/contracts/agent_registry/src/lib.rs (line ~335)	register_agent — where to add limit check
smart-contracts/contracts/agent_registry/src/lib.rs (GasConfig)	Pattern for admin-configurable params

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💥 Impact

• Each agent record costs persistent storage rent on Stellar
• Capability index Vec<Symbol> grows without limit per capability
• lookup_agents iterates the entire vector — expensive for large sets
• No way to know total agent count without full state scan

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✅ Expected Implementation

1. Add Storage Config

#[contracttype]
pub struct StorageConfig {
    pub max_agents: u32,              // Global limit (0 = unlimited)
    pub max_per_capability: u32,      // Per-capability limit (0 = unlimited)
}

2. Add Storage Key

#[derive(Clone)]
pub enum DataKey {
    // ... existing ...
    StorageConfig,  // ADD
    TotalAgents,    // ADD: counter for fast total_agents() reads
}

3. Add Validation in register_agent

pub fn register_agent(env: Env, record: AgentParams) -> Result<(), Error> {
    // ... existing checks ...

    // Check global limit
    let config = get_storage_config(&env);
    if config.max_agents > 0 {
        let total = get_total_agents(&env);
        if total >= config.max_agents {
            return Err(Error::StorageLimitReached); // New error variant
        }
    }

    // Check per-capability limit
    if config.max_per_capability > 0 {
        let cap_index = get_capability_index(&env, &record.capability);
        if cap_index.len() >= config.max_per_capability {
            return Err(Error::CapabilityLimitReached); // New error variant
        }
    }

    // ... rest of registration ...
}

4. Add Read Function

pub fn total_agents(env: Env) -> u32 {
    get_total_agents(&env)
}

pub fn get_storage_config(env: Env) -> StorageConfig {
    env.storage()
        .instance()
        .get(&DataKey::StorageConfig)
        .unwrap_or(StorageConfig { max_agents: 0, max_per_capability: 0 })
}

5. Add Admin Configuration

pub fn set_storage_config(env: Env, config: StorageConfig) {
    let admin = get_admin(&env);
    admin.require_auth();
    env.storage().instance().set(&DataKey::StorageConfig, &config);
}

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📁 Reference Patterns

File Path	Pattern
smart-contracts/contracts/agent_registry/src/lib.rs (GasConfig)	How admin-configurable params are stored
smart-contracts/contracts/agent_registry/src/lib.rs (set_gas_config)	Admin auth pattern

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✅ Acceptance Criteria

• Add StorageConfig struct with max_agents and max_per_capability
• Add DataKey::StorageConfig and DataKey::TotalAgents storage keys
• Add total_agents() read-only function
• Add get_storage_config() read-only function
• Add set_storage_config(config) admin function
• Add validation in register_agent for global limit
• Add validation in register_agents batch for global limit
• Add StorageLimitReached and CapabilityLimitReached error variants
• Add unit tests for hitting limits
• Add unit test: total_agents increments on registration
• Add unit test: non-admin cannot set storage config

[nurudeenheroic]

Hello! I'd appreciate the opportunity to work on this issue.I've gone through the issue and am ready to get started.