feat(admin): /dispatch graph, the topology as text (issue #54)

[edgehero]

Fourth slice of issue #54: the graph's first consumer. Stacked on #167 (merged).

What

• renderGraph (pure, render.mjs): folder groups, triggers with run stats and dangling badges, skills with reachability badges, and edges labelled by their evidence class — then the honesty counters and the caps line, which renders always: edges without their bounds invite the reader to extrapolate an unbounded chain fabric out of a depth-1, width-2 reality.
• assembleGraph (index.ts, the assembleCosts twin): triggers read fresh every call (OQ-008: a cached topology is a stale topology), resident schedulers, one bounded record scan, the enumerations through collectGraphInputs, then the pure fold. All I/O stays in the read-model.
• case "graph" in the subcommand switch, KNOWN_SUBCOMMANDS + USAGE + completions. Deliberately not an LLM-callable tool (the enumeration spawns git per folder; DES-CLI-SURFACE's operator-typed ungated tier; the registered-tool count pin stands).
• readTriggers now also returns the raw entries count — the attribution range guard must accept an index pointing at an unusable-but-present row.
• New wiring pin: USAGE and KNOWN_SUBCOMMANDS agree member-for-member — two copies of one list that nothing pinned together until this amendment widened both.

Specs (same PR)

NEW REQ-TOPOLOGY-GRAPH: the honesty rules as requirements, on the REQ-COST-ANALYTICS precedent (the estimate-never-mislabeled-as-truth discipline applied to topology: a mention must never read like history, a stale index must never land on today's row, a capped scan must never read as complete coverage). REQ-ADMIN-VIA-PI-EXTENSION and DES-ADMIN-VIA-PI-EXTENSION AMENDED (command list). REQ-COST-ANALYTICS UNCHANGED, checked.

Docs

New docs/graph.md (edge/badge reference with the honesty rules in operator words), README and docs/workflows.md cross-links (no dashes as punctuation).

Tests

Canned-model render block (header anchored, exact-equality empty render, truncation/dropped-edge surfacing, negative claims: a potential line never borrows observed's vocabulary, no matched-label text anywhere); the offline-deterministic channel wiring test (unparseable VALKEY_URL degrades synchronously — a dead port would leak a stray async error event into the runner, which is exactly why this suite never opens real connections); the agreement pin; completion coverage. Suite in the CI posture: 2120 pass, 0 skipped; admin bundle builds.