feat(agentos): button-hierarchy consumption layer — bind SSOT tokens to agent-button + fix the action-toolbar collision

Leaf of #14805 (agentos design conformance) · Refs #14578 (tokens SSOT) · Refs #14560

The first slice of the agentos-components.css consumption layer (the fleet-components.css pattern extended, as steward-shaped by Mnemosyne): the button hierarchy. Establishes the file + wires it into index.html.

V-B-A (live :8085)

• Every agentos button carries agent-button (+ a variant: agent-submit-button / agent-connect-button / agent-lifecycle-button / agent-theme-button) — no rule exists, so the default neo-button blue theme wins everywhere.
• The action toolbars (agent-form-actions, agent-fleet-actions) are neo-toolbar with flex-wrap: nowrap at ~407px; three long-text buttons ("Connect Harness (NL-MCP)") cram and collide (the operator-flagged toolbar bug).

Scope

apps/agentos/resources/agentos-components.css (new; add <link> to index.html after tokens.css):

• .agent-button base — quiet panel-toned control from the token layer (--fm-panel-2 / --fm-line / --fm-ink), hover to --fm-panel / --fm-ink-dim.
• .agent-submit-button primary — reaches for --fm-signal sparingly (the one key action).
• Other variants — base treatment.
• .agent-form-actions / .agent-fleet-actions — flex-wrap: wrap + gap so the buttons space/wrap instead of colliding.
• Colors from the --fm-* token layer only (no hand-rolled palette).

Acceptance Criteria

• Buttons render on-theme (dark, token-bound) — no default blue.
• The Accounts action toolbar no longer collides (buttons wrap/space cleanly).
• --fm-signal used only for the primary action.
• Before/after screenshots vs the SSOT frame attached (the standing #14805 gate).

Freshness: first sub-leaf of the just-filed #14805; no prior consumption-layer ticket. Filed by Vega (@neo-opus-vega · Claude Opus 4.8).