Close Milestone 3 with measured projection evidence

SLICE_HISTORY.md

@@ -1,5 +1,51 @@
 # Completed slices
 
+## DocForge2 Milestone 3 independent projections
+
+### Changed
+
+- Added strict version-1 manual plan, graph plan, projection package, and projection receipt
+  contracts with canonical identities and packaged schemas.
+- Kept the legacy manual API and exact alpha bytes as a compatibility wrapper over a pure planner,
+  immutable package, and independent renderer.
+- Added generation-pinned portable graph planning, detached rendering, content-addressed durable
+  publication, repair, and receipt-only status.
+- Added a fixed isolated worker protocol with bounded request, response, artifact, timeout,
+  environment, and renderer inventory.
+- Added semantic manual fragments with independent worker validation, corruption recovery,
+  full-render equivalence, and bounded cache retention.
+- Added version-2 independent manual, portable-graph, and live-viewer policy with descriptor-bound
+  generated-client evidence while retaining effective policy version 1.
+- Corrected live source reads to use the pinned index generation.
+- Added static and interactive accessibility gates for the manual, portable graph, and live viewer.
+- Replaced recursive cycle planning with an iterative traversal proven at 10,000 nodes.
+
+### Verification
+
+- The complete gate passed 281 tests, 272 subtests, three accessibility flows, dependency checks,
+  builds, and all milestone smoke benchmarks.
+- The maintained projection contract subset passed 142 tests and 236 subtests.
+- The clean ten-sample 1,000-node benchmark passed every latency, memory, response-size, no-work,
+  deterministic-output, and full/incremental equivalence threshold.
+- An isolated wheel passed CLI, MCP, detached manual rendering, and malformed worker startup.
+- Three adversarial review tracks were reconciled, and Gitleaks found no findings in the six
+  milestone commits or candidate tree.
+
+### Limits
+
+- Production fragment reuse is correct and recoverable but is slower than forced full rendering at
+  the maintained 1,000-page fixture. No speedup is claimed.
+- Actual detached artifact transfer is capped at 20,000,000 bytes.
+- Portable graph publication is CLI-owned. MCP exposes read-only plan and status tools.
+- Remote render services, render farms, third-party renderer ecosystems, storage replacement,
+  self-hosting, adapter SDK expansion, and production integration changes remain out of scope.
+- No tag or release was created.
+
+### Next gate
+
+Milestone 4 remains directional and is not active. Create a new active-slice contract before
+starting adapter SDK or product-documentation implementation.
+
 ## DocForge2 Milestone 0 successor foundation
 
 ### Changed