Finalize bounded typed pipeline implementation

docs/internal/pipeline.md

@@ -142,7 +142,8 @@ The runner:
    source document;
 3. obtains or executes the chunk result;
 4. validates and canonicalizes chunks;
-5. executes each resolved artifact lane in order;
+5. dispatches extract jobs in source-chunk then resolved-lane order, starting a
+   bounded lane continuation when all extracts for that lane are terminal;
 6. invokes the prepared output encoder and validates its logical file results;
 7. returns the assembled manifest, outcomes, warnings, and files.
 
@@ -161,6 +162,13 @@ and validators while performing these transitions:
 Module-provided warnings and payload warnings are promoted only from attempts
 whose results are accepted and used.
 
+The extract job channel has the same capacity as the effective extract worker
+count, so dispatch applies backpressure. A fixed continuation executor prevents
+ready or checkpoint-reused lanes from creating one goroutine each. Workers and
+continuations publish lane-local results; the coordinator is the only writer of
+aggregate output and merges those results in resolved lane and source-chunk
+order.
+
 ## Chunk Canonicalization
 
 Before lane execution, generic validation requires unique chunk IDs, matching
@@ -234,6 +242,12 @@ time. Successful status reflects whether any result was rejected. The
 durable manifest and logical file schemas are defined in the
 [JSON output contract](../integrations/json-output.md).
 
+On a framework failure, the runner cancels its derived context, stops submitting
+new extract work, drains started tasks, and skips the output encoder. Parent
+cancellation takes precedence. Otherwise context-cancellation fallout is
+discarded when a substantive error exists, and the primary error is selected by
+stage, resolved lane, and source chunk rather than completion time.
+
 ## Tests To Inspect
 
 - `internal/core/config/effective_config_test.go`: config-to-resolution boundary.
@@ -244,6 +258,9 @@ durable manifest and logical file schemas are defined in the
 - `internal/framework/pipeline/typed_resolution_test.go`: heterogeneous typed
   lane resolution and preparation, target-specific validators,
   incompatibilities, ordering, and schema-sensitive pipeline identity.
+- `internal/framework/pipeline/runner_concurrency_test.go`: bounded dispatch and
+  continuations, reverse completion, stable errors, rejection, cancellation,
+  retries, and independent provider-call limits.
 - `internal/framework/pipeline/preparation_test.go`: option validation,
   construction order, dependency failures, and the before-source-work boundary.
 - `internal/framework/pipeline/references_test.go`: target resolution and