fix(consensus): fix bootstrap stuck at genesis after blocksync mode changes

Two issues prevented consensus from starting at bootstrap:

1. TendermintNewHeight was incorrectly guarded by blocksync mode check,
   preventing state machine initialization. State must be initialized
   regardless of mode - only active participation should be blocked.

2. Resume handler did nothing when is_paused=false (initial state).
   At bootstrap, enter_consensus_mode sends Resume but resume_consensus
   returned early due to the is_paused guard, so start_height was never
   called and no timeouts were scheduled.

Fixes:
- Remove blocksync guard from TendermintNewHeight handler
- Set is_paused=true before resume_consensus to ensure execution
- Handle height==current_height case for bootstrap/WAL recovery scenarios

Author: michaelgpt

app/src/actors_v2/chain/handlers.rs

@@ -2052,21 +2052,10 @@ impl Handler<ChainMessage> for ChainActor {
 
                 let actor = self.clone();
                 Box::pin(async move {
-                    // TM-B5 Fix: Check consensus mode - skip height init during blocksync
-                    // NewHeight is part of startup/recovery, so we queue it implicitly
-                    // by not processing until consensus mode is entered
-                    let mode = actor.get_consensus_mode().await;
-                    if mode == ConsensusMode::Blocksync {
-                        debug!(
-                            correlation_id = %correlation_id,
-                            height = height,
-                            "TendermintNewHeight deferred - in Blocksync mode"
-                        );
-                        // Return success but don't actually initialize
-                        // The height will be initialized when entering consensus mode
-                        return Ok(ChainResponse::TendermintHeightStarted { height, round: 0 });
-                    }
-
+                    // TM-B5 Fix Note: TendermintNewHeight MUST be processed regardless of mode.
+                    // This initializes the state machine - without it, consensus can never start.
+                    // The mode guards on TendermintPropose/Timeout prevent active participation
+                    // during blocksync, but the state machine must be initialized.
                     let (height, round) = actor
                         .handle_tendermint_new_height(height, correlation_id)
                         .await?;

app/src/actors_v2/tendermint_driver.rs

@@ -1038,22 +1038,26 @@ impl Handler<TendermintDriverMessage> for TendermintDriver {
                         resume_height = height,
                         "Resuming consensus at new height after sync"
                     );
+                    // Need to set is_paused so resume_consensus will execute
+                    self.is_paused = true;
                     self.resume_consensus(height, ctx);
-                } else if self.is_paused {
-                    // Same or lower height but we're paused - just unpause
+                } else if height == self.current_height {
+                    // TM-B5 Fix: Same height - restart consensus round
+                    // This handles bootstrap case where initial proposal was rejected
+                    // due to blocksync guards, but now we're in consensus mode.
                     info!(
                         current_height = self.current_height,
-                        requested_height = height,
-                        "Unpausing consensus at current height"
+                        "Restarting consensus at current height after sync"
                     );
-                    self.is_paused = false;
-                    // Re-schedule timeout for current position
-                    self.schedule_timeout(ctx);
+                    // Force restart by setting paused and calling resume
+                    self.is_paused = true;
+                    self.resume_consensus(height, ctx);
                 } else {
+                    // height < current_height - stale resume, ignore
                     trace!(
                         current_height = self.current_height,
                         requested_height = height,
-                        "Resume ignored - already running at higher height"
+                        "Resume ignored - already at higher height"
                     );
                 }
             }