Loki Mode v7.28.2

Changed (first-run UX, from the 2026-06 user-shoes friction audit)

• Bare loki now prints an 11-line newcomer landing (what Loki Mode is, the
  three commands that matter, a provider-prerequisite pointer to loki doctor
  placed before any paid action, and a cost-preview tip) instead of the
  168-line full command table. loki help and loki --help are unchanged.
• loki doctor timing label corrected from "(instant)" to "(a few seconds)"
  (measured 3.2-4.4s across routes).
• loki dashboard start and loki web each print one line distinguishing the
  two browser UIs (run monitor on 57374 vs project web UI on 57375).
• The bundled demo PRD (templates/simple-todo-app.md) now classifies SIMPLE
  (score 0, ~4 iterations, $1.86 estimate) instead of COMPLEX ($9.30),
  matching what loki demo actually runs.
• README "Get Started in 30 Seconds" leads with the 3-line happy path;
  prerequisites collapse below it with an honest provider-CLI note.
• 16 missing-required-argument usage errors standardized to exit 2 (was a mix
  of 1): provider set, issue parse, issue view, run, issue, config set,
  config get, quick, plan, notify, heal, migrate, and the enterprise token
  subcommands. Help-flag exits are unchanged. Caller analysis confirmed no
  internal consumer branches on the old code; exit 2 is the POSIX
  usage-error convention.
• Fixed a dead anchor: docs/alternative-installations.md pointed at a
  nonexistent README #installation heading.

Tests

• tests/test-cli-commands.sh: 23/23 on both routes. tests/test-plan-command.sh:
  16/16. scripts/local-ci.sh: full run green.