Every Synapse event used to open its own service session, so two messages of
one Telegram chat landed in two unrelated chats. The dispatcher now returns a
`session_key` — derived from the payload according to the user's routing
document — and a later event carrying the same key joins the session that
opened it, within `reaction_session_ttl_minutes` of idle time (0 restores the
old always-fresh behaviour). A session that is still running is never joined:
`create_run` overwrites `state.run`, so a second run would orphan the first
one's subscribers — a busy thread gets a fresh session instead. When the
dispatcher names a different profile for the event, the session's profile is
switched through `set_profile`, never through `save()`, which does not rewrite
`name` or `profile_id`: the thread keeps its name and its history.

What the user reads in the transcript is now only the request. The event
record is a system message (`metadata.source == "synapse_event"`) drawn by a
new SynapseEventNotice.vue in the visual language of the recall badge, and the
framing plus the JSON envelope become a hidden user turn written once, on the
first event of a thread — not on every one. The instructions from Settings
reach the model through a new `current_reaction_instructions` ContextVar and
the `[Reaction session]` block of the system prompt, so they appear in no
transcript at all. The stored system record still has to reach the model, so
ContextBuilder's allowlist becomes `_LLM_SYSTEM_SOURCES = {task_note,
synapse_event}`.

The dispatcher gets a document of its own — how to route, rather than what to
do — stored beside the reaction instructions, versioned separately, and edited
in its own field in the settings panel. `synapse_instruction_versions` gains a
`doc` discriminator, so existing rows keep `'reaction'` and their history
verbatim. The new columns are added by `_MIGRATE`, and the index over `doc`
lives there too: `_DDL` runs first, so an index over a column the migration has
not added yet kills the whole batch on an existing database — which is what
the prod database is. A guard test keeps it that way.

Tests: 1776 passed, 1 skipped (backend), 242 passed (webclient, 28 files).

Settings is the first area off hard-coded English: 122 strings for the shell and
its five tabs — App, Account, Notifications, Synapse and MCP — plus the 43 the
shared vocabulary contributes (common.*, col.*, confirm.*, toast.*).

The English dictionary carries the very literals the templates used, so the
interface a test reads is byte-for-byte what it was and the 56 assertions on
English UI text stay green; only a slug that is genuinely counted had to be
restructured into a plural. In ru and uk the counted strings get the three
Slavic forms driven by n. Product names are never translated: Navi, Synapse,
MCP, Ollama, Tool call, Subagent and Token read the same in all three
languages, and the settings screen keeps one settings.* area with
panel-prefixed slugs rather than a slug per panel, as the other gnexus clients
do.

Strings carrying markup are split around it instead of hiding tags in the
dictionary: the install steps keep their inline icons and <code>http://</code>
in the template, with the words of each sentence on either side. Four lists of
labels — the settings tabs, two table headers, and the reaction options — are
now computed rather than module-level constants, since a list built at import
keeps the language that was active then and ignores a switch. Dates in the
panels go through the interface language as well, not the browser's.

Checked in Chromium against the built bundle: all three languages on all five
tabs, with a scan for a slug leaking into the rendered text as the pass
condition, and the account left with no override afterwards.

The client hard-coded English in every template. It now goes through t() from
src/i18n/ — a locale ref, {param} interpolation, plural dictionaries driven by
n, and flat per-area dictionaries in src/i18n/messages/ carrying the same slugs
in all three languages. vue-i18n is deliberately not pulled in: the platform
handbook rules it out, and what it would buy — plural forms, a reactive locale,
an English fallback — is about eighty lines here. A slug nobody carries falls
back to English, so a screen already translated and one still speaking
hard-coded English can coexist while the work goes area by area.

The language comes from locale_effective in GET /auth/me: the choice made in
Settings (navi_users.locale_override, a new column) over the gnexus-auth
account locale (navi_users.locale, a straight mirror the user.profile_updated
webhook keeps writing — the override sits in its own column precisely so that
mirror cannot wipe it), over en. PATCH /auth/me writes the override, and null
means "follow the account" again. With NAVI_AUTH_ENABLED=false there is no
account to follow, so the choice is kept in localStorage under navi.locale.

The picker is the first block of Settings → Account. Each language is named in
its own language, which is why those three strings are identical in all three
dictionaries. Lists of labels are computed rather than module-level constants:
one built at import would keep the language that was active then and ignore a
switch.

Checked in Chromium against the built bundle: choosing Русский rewrites
<html lang> and the document title, survives a reload, and Auto brings the
account's own language back.

Settings gains an App section: how to install Navi in the browser — a real
Install button where the browser offers beforeinstallprompt, per-platform
steps where it cannot, since Safari and Firefox never expose that API and iOS
goes through the share sheet — and the Android APK, with its version, size and
checksum, behind a download the app hands to the system browser. The PWA
listener is armed from main.js because beforeinstallprompt fires once, during
startup, long before the panel is ever mounted.

App is now the first tab and every section is linkable: #settings/app,
#settings/mcp, and so on. Parsing moved into utils/hash.js, which the three
places in App.vue that route on the hash now share — before it, #settings/app
was read as the id of a session and opened an empty chat. Switching tabs
rewrites the address with replaceState, so Back leaves Settings instead of
walking back through the tabs, and a bare or unknown #settings normalises to
the first tab.

Checked in Chromium against both the dev server and the built bundle: each
hash opens its section, no /api/sessions/ request is ever made for one, a tab
click leaves history.length alone, and at 390 and 320px the strip keeps five
tabs with the active one scrolled into view and no sideways overflow.

`is_admin_only` was checked in one place out of nine and was not read from
config.json at all, so all seven profiles were reachable by every account with
role `user`. The flag now lives in config.json — the file is the baseline, a
`profile_overrides` row still wins on top of it — and one predicate,
`admin_only_blocked`, is the single place the rule is expressed. The nine
surfaces that list, switch to, spawn or resolve a profile all consult it:
`POST /sessions`, the WebSocket, switch_profile, list_profiles, the system
prompt's "Available profiles" block, spawn_agent and the Synapse reaction
runner. The prompt cache is now keyed by (profile, role), so a user's prompt
can never be served an admin's profile list.

The seven existing profiles (developer, discuss, dispatcher, modeler_3d,
navi_code, secretary, server_admin) are marked admin-only. Three new ones take
their place for ordinary users: assistant, designer_3d and coder. They share one
native tool set — ssh_exec, peer, reload_tools, create_mcp_server, test_mcp_tool,
image_view and gmail are withheld — and differ only in system prompt, model and
MCP groups. navi-web's raw `request` group, and the whole of gnexus-creds and
tgclient, are withheld too.

MCP per-user keys gain the missing half of the rule: a server that declares a
`user_key` slot is refused to anyone but an admin who has no personal key, and
is left out of their tool list entirely, instead of quietly falling back to the
owner's credential and appearing as a tool that cannot work. The refusal names
the server and points at Settings.

Also closes `GET /agents/prompts`, which served every profile's system prompt to
anyone, with no user dependency at all.

The accepted residual risk is written down in docs/profiles.md: the working
directory is a convention, not a sandbox.

Settings → MCP gains a Tools block for admins only: one button, then the
same report the tool prints — what loaded, how many are in the registry,
per-file errors, and names in enabled.json nothing answers to.

It sits inside the existing MCP tab rather than a new one: the reload
rewrites the toolset of the whole server, not just this user's MCP keys,
and it belongs next to the thing it affects. Non-admins never see it.

dist rebuilt together with the source, as the server serves the bundle.

The tab was empty on every install: it listed only servers whose config
declares a `user_key` slot, and no config declared one — which read as
"no MCP servers connected" even though five are wired to profiles.

- GET /mcp-keys now returns every server referenced by at least one
  profile, keyed ones first, with `accepts_user_key`, the slot location
  (null when there is none) and the profile ids that connect it. The
  per-user key store is skipped entirely when nothing has a slot.
- gnexus-creds declares `user_key: {header: Authorization, prefix:
  "Bearer "}` — it is the one server carrying a shared credential, so its
  personal-key field is now real: users with a key run under their own,
  users without one fall back to the shared default.
- The panel lists all servers (transport + profiles), dims the keyless
  rows, and shows a key input only for slotted ones, spelling out the
  shared-key fallback.

docs/api.md and docs/mcp.md updated; backend 1367 passed, webclient 148.