v0.7.1

myco query is now the frictionless first-class way to explore the graph, and
the docs are reframed to match. Non-breaking.

myco query — first-class, no jq, no schema knowledge

• Default hub via $MYCELIUM_HUB. --url now defaults to $MYCELIUM_HUB, so
  myco query <name> needs no flag — set the env var once and query the live graph
  directly. An explicit --dir still selects a local artifact over the ambient hub.
• Flags work in any position. myco query used-by config-core --url <hub> no
  longer silently drops the trailing flag — the CLI loop-parses so flags and the
  positional can interleave.
• A real error when no source is configured. No --url, no $MYCELIUM_HUB, and no
  local graph.json now yields "no graph source: set $MYCELIUM_HUB … or pass
  --url/--dir" instead of a cryptic open graph.json: no such file.

Docs reframed to the real hierarchy

MAP.md (its generated preamble), README, and schema/graph.md now lead with the
same model: read MAP.md to orient → query with myco query (first-class, no need
to know the JSON shape) → hand-written jq over the raw graph.json for
specific/programmatic cases only → /q/* over URL is a bonus for when the binary
isn't around.

Full Changelog: v0.7.0...v0.7.1