[gabewillen]

Summary

Brings cortext.go up to date with augmem/cortext.cpp main (f0b681e9: engine v5 #28, per-blob content timestamps #30, reference-time retrieval #31). The branch starts from the local engine-prune work (evidence budget, standing_memory, typed and mixed content, ProceduralEnabled removal), merges origin/main (already contained, so no changes) and merges PR #1 (feat/text-media-payload).

Requires the next engine release. AssetsVersion / ModuleVersion stay at 1.2.4, and the CHANGELOG "Unreleased" section says so. With the pinned native, the v5 tests skip.

Per API item

• Evidence budget: ProcessOptions.EvidenceBudgetBytes → evidence_budget_bytes, on every Process* call (from engine-prune).
• Reference time (new):
  • ProcessOptions.ReferenceTime time.Time and AsOf bool map to has_reference_ms / as_of / reference_ms. The native struct is 48 bytes, and a test pins its layout.
  • The zero ReferenceTime means unset.
  • AsOf without ReferenceTime is an error, and so is a time before the epoch.
• Standing memory: returned as ctx["standing_memory"] and documented. A new test checks that it holds the directive and not the fact.
• Mixed modality / per-content MIME type: modality: "mixed", per-entry mimetype, and the memory mimetype taken from its first signal. Documented, with an existing test.
• Per-content timestamps (new): documented content[].timestamp (ms, 0 = unknown). A test checks it falls within the store window.
• Text with media (from feat: add text processing with media payloads #1):
  • Merged as is, then the docs were corrected: media replaces the stored payload, empty media stores the text, and text/* payloads count as text.
  • It takes ProcessOptions, so the budget and reference time apply.
  • The optional-symbol guard for natives without the entry point is kept.
• LI model asset (new):
  • MaterializeModel checksums AIST-87M-LI.gguf and places it beside AIST whenever the manifest declares it. Older manifests that don't declare it are skipped.
  • It can install from an already-assembled file as well as from chunks.
  • New validates CORTEXT_LI_MODEL_PATH and forwards it through the CRT on Windows.
• Older natives:
  • Options that a loaded native cannot read now return an error instead of being ignored.
  • Process options are offered in each known layout, newest first. Before this, released natives clipped the 32- or 48-byte struct to the include_embedding prefix and silently dropped retention.
  • New rejects SequentialEdgesEnabled / SignalFilter* on a pre-v5 native, because there they would land one field off.

Breaking

• Config.ProceduralEnabled is removed (a change to the C cortext_config layout).
• Soft Anchors are gone from the packet.
• There is no longer a 3 KiB per-memory trim: memories come back whole unless a budget is set.
• v5 engines require the LI reranker whenever AIST resolves.
• Options or Config fields that the loaded native cannot honour now return errors.

Test plan

All runs used CGO_ENABLED=0 go test ./... -count=1 on macOS arm64 with Go 1.26.0.

• Against the local engine (CORTEXT_LIBRARY_PATH=/Volumes/Build/cortext/bindings/shared/libcortext.dylib built from f0b681e9, CORTEXT_ASSETS_DIR=/Volumes/Build/cortext/bindings/models, CORTEXT_LI_MODEL_PATH=…/AIST-87M-LI.gguf): 26 passed, 0 skipped, 0 failed (ok … 375s).
• Release native only (no env overrides, pinned 1.2.4 downloaded, as in CI): 16 passed, 10 skipped (v5-only), 0 failed (ok … 466s). TestNewProcessEmbed now also asserts that the 1.2.4 native keeps the retention layout and rejects shifted Config fields.
• -short: ok.
• The v5 native tests (reference time, timestamps, text with media, standing memory) were run 5 times (-count=5): ok.
• Red then green:
  • With the API surface stubbed (fields present but not wired), the reference-time options test, AsOf hiding, the older-native error, LI materialization and LI env validation all failed. They pass after the change.
  • Against the previous cortext.go, the legacy-layout test showed StructSize:12 … Retention:3 (retention dropped), and the Config guard accepted shifted fields. Both pass now.
  • The packet-shape tests (timestamps, text with media, standing memory) pin engine behaviour through existing binding calls. They were green on first run because they need no binding change.

Not verified: Windows and Linux (CI only), and 32-bit (the layout test skips there).

Supersedes #1.