fix(distribution): install DSH plugin without build scripts - #86

Root cause

The Hub cannot find a DSH-compatible npm release, so it correctly falls back to a Git dependency. That exposed two independent install-time script boundaries:

1. graph-memory used prepare to compile TypeScript after a Git fetch.
2. @photostructure/sqlite used a native install lifecycle even when consuming prebuilt tarballs.

pnpm 11 rejects both unless every user mutates the profile allowBuilds policy. Fixing only one still leaves installation broken.

Systemic fix

• use Node 22 built-in node:sqlite, the same runtime boundary used by current DSH;
• centralize SQLite ownership behind src/store/sqlite.ts;
• remove all install-time lifecycle scripts and native runtime dependencies;
• commit the small generated dist runtime so GitHub installs load prebuilt code;
• keep prepack for release builds;
• add a reusable package verification gate that rejects install lifecycles, runtime dependencies with install scripts, missing packed entries, and stale generated output;
• update installation docs and bump the beta to 1.6.0-beta.9.

Verification

• 17 test files / 130 tests pass;
• TypeScript and DSH builds pass;
• package verification reports 75 packed files and no install-time scripts;
• real pnpm 11.7.0 plus a fresh DSH Web profile installs directly from a Git commit without creating allowBuilds;
• DSH discovers graph-memory/dsh, loads the plugin, and creates the Graph Memory database.

Closes #82
Closes #83
Closes #84