scaffold v0.1: postgres+pgvector inside-container, schema, markdown ingest, CLI

Skald is a generic story-writer. The database is the product; the
binary is the tooling. Everything story-specific lives in rows, not
in code. cwho's monorepo + binary-per-role pattern transplanted to
this domain.

What this commit ships:
- Cargo workspace (resolver=3, edition 2024): skald-core (lib) +
  skald (bin)
- Migration 0001: stories, characters, canon_facts, chapters,
  chapter_summaries, passages (vector(1536)), generation_runs,
  audit_findings, tags. pgvector + pg_trgm extensions. ivfflat
  index deferred until we have data (post-import the first ~1k
  passages and add the index).
- skald-core::ingest — markdown parser for the cwho/coast-down shape:
  '# Title' → '## Chapter N — date' headings → '# Continuity Bible'
  section with character roster (real + fictional sub-sections) +
  setting / mystery / historical / liberty / hook sub-sections.
  Decomposed into structured rows; original bullet body preserved
  in key_facts/body fields for fidelity. 6 unit tests cover the
  shape.
- skald-core::db — Postgres connection pool + migration runner.
- skald-core::models — row types via sqlx::FromRow.
- skald binary — clap CLI: 'serve' (http + migrations) and
  'import-markdown' (one-shot ingest).
- Dockerfile — multi-stage: rust:1.95-bookworm builder, pgvector/
  pgvector:pg17 runtime, tini under PID 1, custom entrypoint.sh
  that boots embedded postgres then execs skald serve.
- compose.yml — singleton container, postgres data in volume,
  story corpus mounted read-only at /seed.

Decisions locked 2026-05-13:
1. DB in same container 'till we have a real working tool' (Sulkta)
2. postgres+pgvector (NOT sqlite) — keeps semantic-search story
3. Network-not-socket connection (postgresql://localhost:5432) from
   day one so future split is config-only, not code-rewrite

Not yet wired:
- Web UI
- clawdforge calls (gen → cleanup → canon-audit pipeline)
- Embedding pass
- TTS sidecar

Dockerfile

@@ -0,0 +1,59 @@
+# Multi-stage build for skald.
+#
+# Stage 1: compile the rust binary against rust:1-bookworm.
+# Stage 2: pgvector/pgvector:pg17 (debian-bookworm postgres with
+#          pgvector preinstalled) + tini + the skald binary.
+#
+# v0.1 ships postgres inside the same container ("singleton till we
+# have a real working tool"). When we extract the DB out, swap the
+# runtime base to debian:bookworm-slim, drop entrypoint.sh, point
+# DATABASE_URL at the external pg.
+#
+# Build context is the workspace root:
+#   docker build -t skald:latest .
+
+# ─── builder ──────────────────────────────────────────────────────
+FROM rust:1.95-bookworm AS builder
+WORKDIR /build
+
+# Cache the dependency graph: copy manifests first, fetch + build
+# stubs, THEN drop in real sources.
+COPY Cargo.toml Cargo.lock ./
+COPY skald-core/Cargo.toml skald-core/Cargo.toml
+COPY skald/Cargo.toml      skald/Cargo.toml
+COPY migrations            migrations
+
+RUN mkdir -p skald-core/src skald/src \
+ && echo 'pub fn placeholder() {}' > skald-core/src/lib.rs \
+ && echo 'fn main() {}'            > skald/src/main.rs \
+ && cargo build --release -p skald \
+ && rm -rf skald-core/src skald/src
+
+COPY skald-core skald-core
+COPY skald      skald
+
+RUN touch skald-core/src/lib.rs skald/src/main.rs \
+ && cargo build --release -p skald
+
+# ─── runtime ──────────────────────────────────────────────────────
+FROM pgvector/pgvector:pg17 AS runtime
+
+# tini for sane signal handling / zombie reaping under PID 1.
+RUN apt-get update \
+ && apt-get install -y --no-install-recommends tini ca-certificates \
+ && rm -rf /var/lib/apt/lists/*
+
+COPY --from=builder /build/target/release/skald /usr/local/bin/skald
+COPY --from=builder /build/migrations            /var/lib/skald/migrations
+COPY entrypoint.sh                               /usr/local/bin/skald-entrypoint.sh
+RUN chmod +x /usr/local/bin/skald-entrypoint.sh
+
+ENV RUST_LOG=info \
+    SKALD_LISTEN=0.0.0.0:7780 \
+    POSTGRES_USER=skald \
+    POSTGRES_DB=skald
+
+EXPOSE 7780
+
+ENTRYPOINT ["/usr/bin/tini", "--", "/usr/local/bin/skald-entrypoint.sh"]
+CMD ["serve"]