feat(wire,kernel,conversation-store): step grouping via stepId for batched tool calls

Expose a per-step grouping key so a client can render a model's batched/parallel
tool calls (those emitted in one step) as one unit, on both the live stream and
replayed history. Key = branded StepId, derived turnId#stepIndex (0-based).

- [email protected]: required stepId on Turn{Tool,ToolResult}Event; optional stepId on
  Tool{Call,Result}Chunk (generation provenance on the chunk, not the StoredChunk
  envelope — StoredChunk unchanged). [email protected] (re-export bump).
- kernel-runtime: mint stepId per step; stamp on tool chunks + tool events.
- conversation-store: chunk-carried stepId round-trips append/load/loadSince for
  free; reconcile copies it onto synthesized (interrupted) results.
- cli: stepId added to event test fixtures (renderer unchanged).

typecheck clean; 509 vitest + 89 bun; biome 0/0. FE courier reply + reference
snapshots regenerated in ../dispatch-web.

1 files changed, 4 insertions, 3 deletions

diff --git a/bun.lock b/bun.lock
index dd7c6ff..bc33ba7 100644
--- a/bun.lock
+++ b/bun.lock
@@ -23,6 +23,7 @@
       "version": "0.0.0",
       "dependencies": {
         "@dispatch/transport-contract": "workspace:*",
+        "@dispatch/wire": "workspace:*",
       },
     },
     "packages/conversation-store": {
@@ -141,7 +142,7 @@
     },
     "packages/transport-contract": {
       "name": "@dispatch/transport-contract",
-      "version": "0.0.0",
+      "version": "0.1.0",
       "dependencies": {
         "@dispatch/ui-contract": "workspace:*",
         "@dispatch/wire": "workspace:*",
@@ -172,11 +173,11 @@
     },
     "packages/ui-contract": {
       "name": "@dispatch/ui-contract",
-      "version": "0.0.0",
+      "version": "0.1.0",
     },
     "packages/wire": {
       "name": "@dispatch/wire",
-      "version": "0.0.0",
+      "version": "0.1.0",
     },
   },
   "packages": {