The fuzzy provider match falls back to substring containment, so
`slack-custom-bot` contains `slack` and resolved to the Slack OAuth
service. The tool then returned a personal-OAuth authorize URL and
reported success — a user who asked for a shared custom bot got a
Connect button that linked their own account instead. Every service
account id degraded this way (notion-, salesforce-, zoom-, linear-),
always silently.

Guard runs before the fuzzy pass and points at
service_account_get_setup_link. Keys off the id being a service-account
id, not off the integration offering one, so `slack` and `notion` still
resolve for OAuth.

Moves the narrowing predicate out of the integration catalog module so
callers that need only the predicate skip the integrations.json load and
the OAUTH_PROVIDERS walk.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Phx1MLjf8Ui3M3VpwisZds

…ng out

The tool handed back a /integrations/{slug}?connect=service-account URL,
so accepting the agent's offer navigated away from the conversation that
asked for the credential. Adds a `service_account` credential tag that
mounts ConnectServiceAccountModal over the chat; setup_url stays as the
headless/MCP fallback.

The tag carries a provider and no value — the secret is typed into Sim's
own form and never enters the transcript — so the validator gets a branch
alongside secret_input/sim_key rather than falling through to the
value-required check.

Extracts useServiceAccountConnectTarget so the chat and the integrations
page share one source of truth for the connect label and the preview
gate. Custom Slack bots ride the slack_v2 flag; without the shared gate
the chat would have surfaced a setup form the integrations page hides.

Modal is lazy-loaded off the deep path (not the barrel) to keep three
provider-specific setup forms out of the chat's initial chunk.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Phx1MLjf8Ui3M3VpwisZds

…he UI

The in-chat connect button hides itself when the provider's gating block
is preview-hidden (a custom Slack bot needs slack_v2). The tool didn't
check this, so it returned success for slack-custom-bot even when slack_v2
was preview-gated off — the agent said "here's the setup form" and the
button silently rendered nothing, leaving the user with no form at all.

Adds getServiceAccountGatingBlockType as the single source for the
provider→gating-block mapping, consumed by both the tool (server-side, via
getBlockVisibilityForCopilot) and the connect hook (client overlay). When
the gating block is hidden the tool now fails with a fall-back-to-OAuth
message instead of promising an invisible form.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Phx1MLjf8Ui3M3VpwisZds

Removes the VFS auth-metadata exposure and returns connectNoun from the
service_account_get_setup_link result instead. The VFS aggregate was a
second, viewer-independent source of truth that couldn't agree with the
per-viewer preview gate (it always hid slack-custom-bot, even for viewers
with slack_v2 revealed, while the tool accepts it for them). The tool now
resolves the provider, applies the per-viewer gate, and returns either the
in-chat button + connectNoun or a fall-back-to-oauth error — one source of
truth. connectNoun stays DRY via getServiceAccountConnectNoun, shared with
the connect-button label.

The agent now emits the service_account credential tag directly from
intent — like secret_input — instead of round-tripping through a tool.
Removes service_account_get_setup_link (handler, registration, display
title, Go tool def) and restores auth.serviceAccount as the VFS discovery
field so the agent knows which providers support a service account.

The link-vs-tag distinction was the wrong axis: only oauth needs a tool,
because its button carries a minted URL that can't be reconstructed. The
service_account tag carries just a provider name the agent already knows,
so it needs no tool — discovery lives in the VFS (auth.serviceAccount,
GA-only, so slack's preview-gated custom bot is never proactively
offered), and the per-viewer gate lives in the renderer, which renders
nothing when a provider isn't available for the viewer (no OAuth
fallback — a shared credential and a personal one are different intents).

oauth_get_auth_link's service-account-id guard now points at the tag.

Review round on #5786:
- The service-account-id guard threw into the generic catch, which
  overwrote its recovery hint with a "connect manually" message and a
  workspace oauth_url — contradictory signals. It now returns a coherent
  failure directly, before the try, with no oauth_url.
- Normalize spaces/underscores before the check so a readable form
  ("slack custom bot", "google service account") is caught too, not
  passed to the fuzzy OAuth resolver.
- Remove listServiceAccountIntegrationNames — dead after the tool was
  removed (its only caller was the deleted handler's error copy).

Review round on #5786: describeServiceAccountForOAuthProvider used
`getBlock(...)?.preview ?? true`, which treats a GA'd gating block — one
that dropped its `preview` flag, exactly slack_v2's documented migration —
as still gated, so the custom bot would stay omitted from VFS discovery
forever after GA even though the UI shows it. Reuse the canonical
isHiddenUnder(null, block) predicate instead, so a non-preview block is
visible. Adds service-account-gate.test.ts covering preview → omit, GA →
include, and missing → fail-closed with a mocked getBlock (the block
registry is globally stubbed, so the real slack_v2 preview flag isn't
observable through serializeIntegrationSchema).

…tialId

Review round on #5786:
- resolveServiceAccountIntegration only lowercased/trimmed, but the
  oauth_get_auth_link guard normalizes spaces/underscores to hyphens
  before rejecting a service-account id and steering the agent to a
  service_account tag. The chat renderer then couldn't resolve those same
  readable forms ("slack custom bot", "notion_service_account") and
  rendered nothing. Apply the same normalization to the id lookups (raw
  query still used for display-name matches).
- service_account tag validation rejected a blank provider but allowed a
  whitespace-only credentialId, which is truthy — the renderer took the
  reconnect path and tried to rotate a non-existent credential. Reject a
  blank/whitespace credentialId.