feat: add time-locked admin functions with queue, execute and cancel …

contracts/savings-vault/src/events.rs

@@ -21,6 +21,8 @@ pub const EVENT_SCHEMA_VERSION: u32 = 1;
 pub const TOPIC_INIT: &str = "init";
 /// Emitted at the end of a successful `set_admin` call.
 pub const TOPIC_ADMIN_SET: &str = "admin_set";
+/// Emitted at the end of a successful `upgrade` call.
+pub const TOPIC_UPGRADED: &str = "upgraded";
 
 // --- flexible ------------------------------------------------------------
 /// Emitted at the end of a successful `deposit` call.

contracts/savings-vault/src/interest.rs

@@ -84,6 +84,24 @@ pub fn set_rate(env: &Env, caller: Address, rate_bps: u32) -> Result<(), Error>
     Ok(())
 }
 
+/// Internal variant of [`set_rate`] used by `timelock::execute_action`.
+///
+/// Auth has already been verified by the timelock; this function skips
+/// `require_auth` and writes the rate directly.
+pub(crate) fn set_rate_internal(env: &Env, admin: Address, rate_bps: u32) -> Result<(), Error> {
+    if rate_bps > MAX_INTEREST_BPS {
+        return Err(Error::InvalidParameters);
+    }
+    env.storage()
+        .instance()
+        .set(&DataKey::InterestRateBps, &rate_bps);
+    env.events().publish(
+        (TOPIC_INTEREST_RATE_SET,),
+        (admin, rate_bps, env.ledger().timestamp()),
+    );
+    Ok(())
+}
+
 /// The annual interest rate, in basis points. `0` (the default) means no
 /// interest accrues.
 pub fn rate_bps(env: &Env) -> u32 {
@@ -124,6 +142,25 @@ pub fn set_frequency(
     Ok(())
 }
 
+/// Internal variant of [`set_frequency`] used by `timelock::execute_action`.
+///
+/// Auth has already been verified by the timelock; this function skips
+/// `require_auth` and writes the frequency directly.
+pub(crate) fn set_frequency_internal(
+    env: &Env,
+    admin: Address,
+    frequency: CompoundFrequency,
+) -> Result<(), Error> {
+    env.storage()
+        .instance()
+        .set(&DataKey::InterestFrequency, &frequency);
+    env.events().publish(
+        (TOPIC_INTEREST_FREQUENCY_SET,),
+        (admin, frequency, env.ledger().timestamp()),
+    );
+    Ok(())
+}
+
 /// The current compounding frequency. Defaults to
 /// [`CompoundFrequency::Annually`] before `set_frequency` is ever called.
 pub fn frequency(env: &Env) -> CompoundFrequency {

contracts/savings-vault/src/lib.rs

@@ -28,6 +28,7 @@ mod challenge;
 mod locked;
 pub mod rewards;
 mod storage;
+mod timelock;
 mod types;
 mod voting;