splus v2: agent-led, engine on tap (v0.9.0)

[ojowwalker77]

The pivot

splus flips from engine-led (push a finding list through a gate) to agent-led (a curious reviewer pulls deterministic signal on demand). The engine becomes a toolbelt, a per-repo contract is read first, and a reviewer's diligence compounds across sessions.

What's in this PR (all wired, no dead code)

P0 — Engine on tap

• inspect engine subcommand + MCP tool: ask one deterministic question — definition · callers · blast_radius · complexity · exports · imports. Reuses the existing analysis tier (graph/symbols/scip/complexity); no new analysis, just addressable.
• floor tool — re-ground on the deterministic finding set for any scope, no directive.
• review recast to orient — injects the contract, returns the floor, drives investigate → verify → report → teach. Backward compatible.
• Import resolver now understands TS ESM .js specifiers (import … from "./x.js" for x.ts) — callers/blast radius now resolve on modern TS, fixing the existing blast-radius collector too. (Dogfood: inspect callers hashEmbedder correctly finds its 2 real callers.)

P1 — splus.md, read first

• Parser + repo/~/.splus layering; injected at kickoff; binding mute:/skip: rules enforced and reported (never silent). preferences tool + prefs skill. A real splus.md ships for this repo.

P2 — Compounding memory

• recall / note, and accept now stores a recallable memory. Embedding match over .splus-cache/memory.json on the existing Embedder seam.

Skills (prime)

• review orchestrator that fans out fresh, unbiased sub-agents per unit (finder ≠ verifier) and degrades to a sequential pass where sub-agents aren't available; investigate / lenses / verify / dispatch references; prefs.

Verification

• ✅ 60 engine tests · 24 TS tests · cargo build --locked (0.9.0) · single-file mcp.cjs bundle parses · no warnings.
• Docs synced: README, docs/TOOLS.md, CHANGELOG. Removed the dead splus-review badge (that workflow was deleted in ci: bump actions off deprecated Node 20; drop self-review workflow #6).

Deliberately deferred (to keep this PR prime, not half-built)

Honest scoping per the "no dead code" bar — the fan-out works today via the skill + the P0/P2 tools, so none of these are dangling:

• Server-side orchestration telemetry (rigor-receipt / coverage-gap gating, P4) — needs runtime fan-out to exercise; the skill drives fan-out without it.
• A transformer embedding model — recall ships on the proven offline Embedder seam; swapping in a model needs to be verified against the single-file offline bundle, which I didn't want to ship unverified.
• Report v2 multi-unit provenance (P5) — the existing report template still works.

---

^{Need help on this PR? Tag /codesmith with what you need. Autofix is disabled.}