feat(phase-1): land IR + plugin loader + server skeleton (D3)

Phase 1 Day 1. First executable code lands. Zero providers wired yet
(per ALIGNMENT.md "v0.1 ships 0 Enabled Providers"); the server starts
clean and POST /v1/chat/completions returns 503 with no_enabled_provider.

Files added:
  lib/ir/types.mjs            - IR v1.0 schema + validators (ADR 0003)
  lib/ir/openai-to-ir.mjs     - OpenAI Chat Completions to IR
  lib/ir/ir-to-openai.mjs     - IR chunks to OpenAI SSE / non-stream
  lib/providers/base.mjs      - Provider contract + validateProvider + ProviderError
  lib/providers/index.mjs     - Static empty registry stub (ADR 0002)
  server.mjs                  - HTTP listener with createOlpServer factory + main guard
  test-features.mjs           - 61 tests across 7 suites (IR / provider / HTTP)

Files modified:
  package.json - main and scripts.start/test added back; targets now exist.

Authority citations:
  IR fields and translation direction: ADR 0003 sections Decision and
    Translation direction model.
  Provider contract (9 fields): ADR 0002 section Provider contract v1.0
    interface.
  Entry surface routes (health, v1/models, v1/chat/completions): OLP v0.1
    spec section 4.1 single-protocol entry; ALIGNMENT.md Authority 2.
  Zero-Enabled-Providers behaviour: ALIGNMENT.md Provider Inventory.

Architectural decisions worth recording:
  1. server.mjs uses a createOlpServer factory plus an import.meta.url
     main guard. The factory returns an unbound http.Server; only the
     main-script invocation calls .listen(). Tests import the real
     server.mjs and exercise the real router. No parallel implementation
     in the test file.

     This pattern was a fold-in from the orchestration step. The initial
     sonnet draft put a top-level server.listen call in server.mjs, which
     forced test-features.mjs to reimplement the router inline (a false-
     confidence trap because the real server logic would never be tested).
     Refactored before reviewer dispatch.

  2. lib/providers/index.mjs ships an empty STATIC_REGISTRY array, not a
     placeholder with dummy entries. ALIGNMENT.md Provider Inventory says
     v0.1 ships zero Enabled Providers; the registry honors that exactly.
     Phase 1 Day 2 adds the first import (Anthropic) when its plugin lands.

  3. BadRequestError lives in openai-to-ir.mjs and ProviderError in
     base.mjs. Reviewer suggested relocating to a shared lib/errors.mjs
     once the count exceeds two; deferred to Phase 1 Day 2 to ship with
     the third typed error class.

  4. contractVersion: '1.0' on each provider plugin: not enforced at D3
     because no providers exist yet. Reviewer flagged for Phase 1 Day 2
     tightening when the first provider lands.

Reviewer chain (Iron Rule 10):
  Initial implementer: sonnet (general-purpose).
  Refactor (createOlpServer + main guard) by the orchestrator after
    catching the inline-router parallel-implementation issue.
  Fresh-context reviewer: opus (ecc:code-reviewer). Verdict
    APPROVE_WITH_MINOR.

Reviewer's two non-blocking findings folded in:
  F1: removed unused createServer import from test-features.mjs line 12,
      left over from the refactor.
  F2: replaced finish_reason value 'error' with 'stop' in both the
      streaming error chunk path (lib/ir/ir-to-openai.mjs line 72) and
      the non-streaming error aggregation path (lib/ir/ir-to-openai.mjs
      line 153). The 'error' value is not in OpenAI's documented
      finish_reason enum (stop / length / tool_calls / content_filter /
      function_call / null), so emitting it would violate ALIGNMENT.md
      Rule 2 (b). Provider errors are now surfaced via a top-level
      response.error object plus an inline content marker. The matching
      test assertion at test-features.mjs line 325 was updated to verify
      finish_reason stays within the OpenAI enum.

Note on the F2 fold-in:
  Reviewer pointed only at the streaming path (line 72). After applying
  that fix I ran grep across lib/ and test-features.mjs for the same
  invention pattern and caught a second hit at line 153 (non-streaming
  aggregation). This is the "fold-in must grep the full repo, not only
  the file the reviewer named" discipline from
  ~/.cc-rules/memory/feedback/evidence_first_under_speed_pressure.md.
  Both hits are fixed in this commit.

Verification:
  node --check on all 7 new files plus modified package.json plus
    server.mjs plus lib/ir/ir-to-openai.mjs - all clean.
  npm test - 61/61 pass in 209ms, no flakes, no skipped.
  OLP_PORT=14001 node server.mjs followed by curl /health returns
    proper JSON; curl /v1/models returns 200 empty list; server shuts
    down cleanly on signal.
  grep "finish_reason.*error" returns zero hits across lib/ and tests.

Co-Authored-By: Claude Opus 4.7 (noreply@anthropic.com)

package.json

@@ -3,6 +3,11 @@
   "version": "0.1.0-bootstrap",
   "description": "Personal multi-provider LLM proxy. Successor to OCP. One HTTP endpoint, multiple subscriptions behind it, automatic routing + fallback + caching.",
   "type": "module",
+  "main": "server.mjs",
+  "scripts": {
+    "start": "node server.mjs",
+    "test": "node test-features.mjs"
+  },
   "engines": {
     "node": ">=18"
   },