v0.116.0: observability pass — always-on debug ring + leveled sweep + agent tab + self-log pull — MinAgent: 0.81.0

Capture layer: LogBuffer always exists; logger = MultiWriter(LevelFilterWriter
(stdout, logging.level), ring) so DEBUG detail exists remotely without a config
flip while docker logs keep respecting the level. New internal/logx leveled
helpers. Report ACK gains controller_log_requested (additive); next report
ships controller_log_tail (128KB, consume-once, app-tail wire byte-compatible).
Debug page: Vezérlő|Ügynök tabs; agent tab proxies agent /debug/logs with the
pre-0.83 notice on typed 404. Sweep: netstorage_job phases, netprobe, handler
validation refusals + orphan WARN, SupportsWithSource gate line, agentapi
per-call DEBUG, migrate phase lines, tier2/offbox unswallowed persists.
Red-proofs: filter-disabled, drain-removed, dropped-phase-line all FAIL.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PSK5g6qYLknKj8u3QAFEr6

controller/internal/web/server.go

@@ -74,6 +74,9 @@ type Server struct {
 	netAgentFn func() (netAgent, error)
 	netProbeFn func(ctx context.Context, dir string) probeOutcome
 	netListFn  func(ctx context.Context) ([]agentapi.NetworkMountStatus, error)
+	// agentLogsFn is the Debug-page agent-tab seam (v0.116.0). nil → the shared
+	// agentClient().DebugLogs; tests inject (incl. the pre-0.83 typed-404 path).
+	agentLogsFn func(ctx context.Context) (agentapi.AgentLogsResponse, error)
 	// netFeatures caches the agent-capability probe (agentapi features.go) for the coupled NAS add
 	// semantics — the add gate + the settings-page banner read it. Zero value ready.
 	netFeatures agentapi.SupportCache