feat: zero-touch Agent — central scheduler, central pause, delta sync, discovery-driven installer

Hub: installations.processing_enabled / sync_interval_seconds / last_sync_* (migration 0026).
The first heartbeat of an installation without coverage queues exactly one INITIAL_SYNC;
afterwards one SYNC_INCREMENTAL per interval (idempotent, backs off on failure). One fiscal
job at a time per Agent (FIFO, stale RUNNING recovery). Job completion now updates the
coverage snapshot, blockers and JOB_STARTED/COMPLETED/FAILED events. Panel: Sincronizar
agora / Reprocessar tudo / Pausar / Retomar + status; pause is enforced Hub-side.
Agent: local AGENT_JOBS_ENABLED is ignored (central control); SYNC_INCREMENTAL re-classifies
only new/changed products via a per-product fingerprint+decision cache and rebuilds coverage
from it; results carry operational summary and blockers; Firebird credentials come from a
DPAPI firebird.bin. Setup: read-only SGV Firebird discovery (auto-select only when
unambiguous, wizard chooser otherwise), starts the service, waits for the first heartbeat,
upgrade-in-place mode. All jobs stay read-only (FIREBIRD_WRITES=0). Version 1.1.3.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

central/app/version.py

@@ -4,5 +4,5 @@ kept identical to this) and what an AgentRelease row's `version` column holds
 once published — never a second, independent version number. Fiscal semantics
 are versioned separately (ENGINE_VERSION/DECISION_VERSION in classification.py,
 DECISION_ENGINE_VERSION etc.) and are NOT changed by a release bump."""
-GTI_FISCAL_VERSION = "1.1.2"
+GTI_FISCAL_VERSION = "1.1.3"
 API_COMPAT_MAJOR_MINOR = "1.0"  # an Agent 1.0.x/1.1.x talks to any Hub 1.0.x