protocol: run a protocol as a committed plan, with a log of how it ended ...

A protocol was only text until now. The new `protocol` tool starts one: its
steps are spliced into the session's todo plan after the agent's current
position (nothing already done is reordered), a row appears in `protocol_runs`
with a snapshot of the version, steps and post-checks, and the run stays
`running` until it is closed.

`finish` refuses while any step of the run is open, refuses outright when one
failed, and requires a report — it is the run's record for the user. `cancel`
and `fail` require a reason and mark the rest of the run's steps `skipped`, so
the plan does not keep work that was never done. One run per session is active
(a partial unique index enforces it).

The commitment also has to survive the context: every model turn while a run is
open carries a system reminder with the protocol, its steps and the way to close
it, and the final-turn intercept now fires for an open run even when the todo
shows no open steps, so a bare-text turn cannot leave one running.

`protocol` is wired into assistant, developer, discuss and server_admin next to
`skills`; sub-agents get neither, because a protocol belongs to the session's
plan. The run log has no UI yet — `protocol(op='status')` is the current view.

skills: agent-written skills and protocol proposals with chat buttons ...

A skill the agent writes now lands in the catalog on its own; a protocol
never does. `skills(op="propose")` stores the document in `skill_proposals`
and returns a card through the tool result's `ui_component` metadata — no
`render_component` call, so profiles without `navi_ui` get the card too.

The decision is the server's: the browser sends `skill_proposal` over the
WebSocket, `SkillStore.decide_proposal` writes the catalog row from the
*stored* document, names the clicking user as the author, and answers with
`skill_proposal_decided`. The agent learns the outcome as a hidden user
message, the same path a `navi_ui` form submission takes.

`create`/`update` refuse protocol documents and point at `propose` with
`replaces_id`, so the version history of a protocol always starts from a
user's yes. The chat store now renders `ui_component` from any tool whose
result carries one, not only from `mcp__navi_ui__render_component`.

skills: catalog of skills and protocols with a settings tab ...

One registry for reusable methodologies: markdown with YAML front matter,
stored in PostgreSQL alongside a full edit history. A row is either a
`skill` (advice, adapt as needed) or a `protocol` (a committed order of
actions), and a protocol is refused on save unless it declares its steps,
post-checks and the three escape hatches — on_deviation, on_blocked,
on_already_done — because an honest run needs a way out when reality
differs from the plan.

- `SkillStore`: lazy DDL, uniqueness on (owner_id, kind, name), version
  bump with an appended `skill_versions` row, `content_hash` as the only
  hive-sync hook. Personal rows carry an owner; shared rows have an empty
  one and are writable by an admin.
- REST `/skills` (list/get/create/update/delete/versions) and the agent
  tool `skills` (search/load) that renders a compact document — numbered
  steps and escape hatches for a protocol, the instructions for a skill.
- Settings → Скилы и протоколы: catalog with search and kind/area
  filters, a document editor that shows the server's validation error
  verbatim, create from a template, delete, edit history, and the
  personal/shared switch for an admin.

Manuals stay where they are: tool knowledge, separate from this catalog.