feat(observability): trace-replay — generic HTTP-exchange record/replay library (39 tests)

New standalone package @dispatch/trace-replay: replayFetch (pure — fixture -> fetch double + captured request, optional chunking to simulate streaming), recordFetch (tees a real fetch into a fixture WITHOUT consuming the caller's stream), and serialize/parse + save/load fixture I/O. Redaction-free by design: calling extensions self-redact in their OWN code before saving (isolation over DRY, D5/§9). Zero @dispatch/* deps, no bun:sqlite (runs under vitest). The shared unit realizing the §7/D5 replay affordance for hermetic provider tests; provider-openai-compat will consume it next.

Root tsconfig ref wired. Verified: tsc -b clean, 327 vitest (288 -> +39: replay 12 / record 8 / fixture 19), biome 0/0. Agent stayed in lane (packages/trace-replay only).

1 files changed, 1 insertions, 0 deletions

diff --git a/tsconfig.json b/tsconfig.json
index a824844..b0fd70a 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -12,6 +12,7 @@
 		{ "path": "./packages/journal-sink" },
 		{ "path": "./packages/trace-store" },
 		{ "path": "./packages/observability-collector" },
+		{ "path": "./packages/trace-replay" },
 		{ "path": "./packages/host-bin" }
 	]
 }