flow: own worker flow state in runtime sessions

Cargo.lock

@@ -1016,6 +1016,12 @@ dependencies = [
  "syn 2.0.117",
 ]
 
+[[package]]
+name = "diff"
+version = "0.1.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "56254986775e3233ffa9c4d7d3faaf6d36a2c09d30b20687e9f88bc8bafc16c8"
+
 [[package]]
 name = "digest"
 version = "0.10.7"
@@ -1243,6 +1249,18 @@ dependencies = [
  "miniz_oxide",
 ]
 
+[[package]]
+name = "flow"
+version = "0.1.0"
+dependencies = [
+ "decodal",
+ "pretty_assertions",
+ "serde",
+ "serde_json",
+ "sha2 0.11.0",
+ "thiserror 2.0.18",
+]
+
 [[package]]
 name = "fnv"
 version = "1.0.7"
@@ -3001,6 +3019,16 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "925383efa346730478fb4838dbe9137d2a47675ad789c546d150a6e1dd4ab31c"
 
+[[package]]
+name = "pretty_assertions"
+version = "1.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3ae130e2f271fbc2ac3a40fb1d07180839cdbbe443c7a27e1e3c13c5cac0116d"
+dependencies = [
+ "diff",
+ "yansi",
+]
+
 [[package]]
 name = "prettyplease"
 version = "0.2.37"
@@ -5962,6 +5990,7 @@ dependencies = [
  "clap",
  "client",
  "dotenv",
+ "flow",
  "fs4",
  "futures",
  "futures-util",
@@ -6005,6 +6034,7 @@ dependencies = [
  "axum",
  "base64 0.22.1",
  "decodal",
+ "flow",
  "futures",
  "llm-engine",
  "manifest",
@@ -6070,6 +6100,12 @@ dependencies = [
  "markup5ever",
 ]
 
+[[package]]
+name = "yansi"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cfe53a6657fd280eaa890a3bc59152892ffa3e30101319d168b781ed6529b049"
+
 [[package]]
 name = "yoi"
 version = "0.1.0"
@@ -6121,6 +6157,7 @@ dependencies = [
  "async-trait",
  "axum",
  "chrono",
+ "flow",
  "futures",
  "manifest",
  "memory",