Slice 2 unblock: pin wire + transport-contract; mirror contracts

- pin @dispatch/wire + @dispatch/transport-contract (+ ui-contract) as file:
  deps @0.1.0; overrides{} workaround for their workspace:* deps (bun can't
  resolve workspace: from outside the monorepo)
- add fake-indexeddb (dev) for the upcoming IndexedDB adapter tests
- mirror wire + transport-contract into .dispatch/*.reference.md for headless
  agents; point package-agent.md at all three references
- backend-handoff.md: convert to a living FE<->backend seam doc

Verified green: svelte-check 0/0, vitest 91, biome clean, build ok; contract
import smoke-test passes.

1 files changed, 17 insertions, 0 deletions

diff --git a/bun.lock b/bun.lock
index 6689953..42819aa 100644
--- a/bun.lock
+++ b/bun.lock
@@ -5,7 +5,9 @@
     "": {
       "name": "dispatch-web",
       "dependencies": {
+        "@dispatch/transport-contract": "file:../arch-rewrite/packages/transport-contract",
         "@dispatch/ui-contract": "file:../arch-rewrite/packages/ui-contract",
+        "@dispatch/wire": "file:../arch-rewrite/packages/wire",
       },
       "devDependencies": {
         "@biomejs/biome": "^2.4.16",
@@ -14,6 +16,7 @@
         "@testing-library/svelte": "^5.2.0",
         "@testing-library/user-event": "^14.6.1",
         "@tsconfig/svelte": "^5.0.0",
+        "fake-indexeddb": "^6.0.0",
         "jsdom": "^25.0.0",
         "svelte": "^5.0.0",
         "svelte-check": "^4.0.0",
@@ -23,6 +26,10 @@
       },
     },
   },
+  "overrides": {
+    "@dispatch/ui-contract": "file:../arch-rewrite/packages/ui-contract",
+    "@dispatch/wire": "file:../arch-rewrite/packages/wire",
+  },
   "packages": {
     "@adobe/css-tools": ["@adobe/[email protected]", "", {}, "sha512-6OzddxPio9UiWTCemp4N8cYLV2ZN1ncRnV1cVGtve7dhPOtRkleRyx32GQCYSwDYgaHU3USMm84tNsvKzRCa1Q=="],
 
@@ -62,8 +69,12 @@
 
     "@csstools/css-tokenizer": ["@csstools/[email protected]", "", {}, "sha512-Vd/9EVDiu6PPJt9yAh6roZP6El1xHrdvIVGjyBsHR0RYwNHgL7FJPyIIW4fANJNG6FtyZfvlRPpFI4ZM/lubvw=="],
 
+    "@dispatch/transport-contract": ["@dispatch/transport-contract@file:../arch-rewrite/packages/transport-contract", { "dependencies": { "@dispatch/ui-contract": "workspace:*", "@dispatch/wire": "workspace:*" } }],
+
     "@dispatch/ui-contract": ["@dispatch/ui-contract@file:../arch-rewrite/packages/ui-contract", {}],
 
+    "@dispatch/wire": ["@dispatch/wire@file:../arch-rewrite/packages/wire", {}],
+
     "@esbuild/aix-ppc64": ["@esbuild/[email protected]", "", { "os": "aix", "cpu": "ppc64" }, "sha512-Hhmwd6CInZ3dwpuGTF8fJG6yoWmsToE+vYgD4nytZVxcu1ulHpUQRAB1UJ8+N1Am3Mz4+xOByoQoSZf4D+CpkA=="],
 
     "@esbuild/android-arm": ["@esbuild/[email protected]", "", { "os": "android", "cpu": "arm" }, "sha512-VJ+sKvNA/GE7Ccacc9Cha7bpS8nyzVv0jdVgwNDaR4gDMC/2TTRc33Ip8qrNYUcpkOHUT5OZ0bUcNNVZQ9RLlg=="],
@@ -296,6 +307,8 @@
 
     "expect-type": ["[email protected]", "", {}, "sha512-knvyeauYhqjOYvQ66MznSMs83wmHrCycNEN6Ao+2AeYEfxUIkuiVxdEa1qlGEPK+We3n0THiDciYSsCcgW/DoA=="],
 
+    "fake-indexeddb": ["[email protected]", "", {}, "sha512-CGnyrvbhPlWYMngksqrSSUT1BAVP49dZocrHuK0SvtR0D5TMs5wP0o3j7jexDJW01KSadjBp1M/71o/KR3nD1w=="],
+
     "fdir": ["[email protected]", "", { "peerDependencies": { "picomatch": "^3 || ^4" }, "optionalPeers": ["picomatch"] }, "sha512-tIbYtZbucOs0BRGqPJkshJUYdL+SDH7dVM8gjy+ERp3WAUjLEFJE+02kanyHtwjWOnwrKYBiwAmM0p4kLJAnXg=="],
 
     "form-data": ["[email protected]", "", { "dependencies": { "asynckit": "^0.4.0", "combined-stream": "^1.0.8", "es-set-tostringtag": "^2.1.0", "hasown": "^2.0.2", "mime-types": "^2.1.12" } }, "sha512-8RipRLol37bNs2bhoV67fiTEvdTrbMUYcFTiy3+wuuOnUog2QBHCZWXDRijWQfAkhBj2Uf5UnVaiWwA5vdd82w=="],
@@ -462,6 +475,10 @@
 
     "zimmerframe": ["[email protected]", "", {}, "sha512-B58NGBEoc8Y9MWWCQGl/gq9xBCe4IiKM0a2x7GZdQKOW5Exr8S1W24J6OgM1njK8xCRGvAJIL/MxXHf6SkmQKQ=="],
 
+    "@dispatch/transport-contract/@dispatch/ui-contract": ["@dispatch/ui-contract@file:../arch-rewrite/packages/ui-contract", {}],
+
+    "@dispatch/transport-contract/@dispatch/wire": ["@dispatch/wire@file:../arch-rewrite/packages/wire", {}],
+
     "@testing-library/dom/aria-query": ["[email protected]", "", { "dependencies": { "dequal": "^2.0.3" } }, "sha512-b0P0sZPKtyu8HkeRAfCq0IfURZK+SuwMjY1UXGBU27wpAiTwQAIlq56IbIO+ytk/JjS1fMR14ee5WBBfKi5J6A=="],
 
     "@testing-library/dom/dom-accessibility-api": ["[email protected]", "", {}, "sha512-X7BJ2yElsnOJ30pZF4uIIDfBEVgF4XEBxL9Bxhy6dnrm5hkzqmsWHGTiHqRiITNhMyFLyAiWndIJP7Z1NTteDg=="],