refactor(cli): convert debug subcommands to effectCmd

[kitlangton]

Summary

Batch-convert 6 debug commands (17 subcommands total) from `cmd()` + `bootstrap()` to `effectCmd` + `Effect.ensuring(store.dispose(ctx))`.

Files:

• `debug/config.ts`
• `debug/skill.ts`
• `debug/snapshot.ts` (3 subcommands: track / patch / diff)
• `debug/lsp.ts` (3 subcommands: diagnostics / symbols / document-symbols)
• `debug/ripgrep.ts` (3 subcommands: tree / files / search)
• `debug/file.ts` (5 subcommands: search / read / status / list / tree)

The parent group commands (snapshot/lsp/rg/file) stay on `cmd()` since they only dispatch to subcommands and don't run handler logic.

Behavioral notes (two parallel subagent purity audits)

Both reviews verdict: BEHAVIORALLY EQUIVALENT for success and ordinary failure paths; STRICTLY SAFER under interruption (Effect.ensuring covers it; legacy try/finally didn't).

Real semantic deltas (consistent with established `models.ts` precedent):

1. No `InstanceBootstrap` run — legacy `bootstrap()` eagerly ran `config.get()` + `plugin.init()` (and forked LSP/File/etc init) before the body. `effectCmd` skips this; services lazy-init on first use. For `debug config` this could surface the raw unmodified config (plugin `config()` hooks haven't run). Same shape as `models.ts`.
2. `Effect.orDie` on Ripgrep typed errors (3 sites in ripgrep.ts, 1 site in file.ts/tree) — the underlying error still surfaces with non-zero exit through the same top-level handler, but defect formatting may differ slightly from a directly-thrown typed error. Cosmetic only.

Followup (not in this PR)

Both agents flagged the 14× repeated `const ctx = yield* InstanceRef; if (!ctx) return; const store = yield* InstanceStore.Service; return yield* body.pipe(Effect.ensuring(store.dispose(ctx)))` boilerplate. Strong suggestion: fold `Effect.ensuring(store.dispose(ctx))` into `effectCmd` itself so per-command disposal is automatic. Worth a separate PR before this pattern spreads further.

Test plan

• `bun run typecheck`
• `bun run test test/cli/` — 137 pass
• Smoke: `debug config` prints config JSON
• Smoke: `debug skill` prints skill list