Give each tracker agent its own config

The tracker-mapping, common-pattern enrichment, and third-party
disambiguation agents were all built from one shared
TrackerAgentsConfig fed by a single tracker-mapping config slot. That
forced a single AgentTimeout to be reused and patched per worker, and
two unrelated max-turns fields to share one struct.

Split the in-code config into TrackerMappingAgentConfig,
TrackerEnrichmentAgentConfig, and DisambiguationAgentConfig, each with
its own timeout and max-turns, and add dedicated tracker-enrichment and
third-party-disambiguation provider slots (the latter resolving next to
third-party-vetter). Enrichment and disambiguation fall back to the
tracker-mapping slot when their own provider is unset, preserving
single-config deployments.

Drop the shared pkg/agentsbuild package and duplicate its small wiring
into probod and proboctl so the two executables stay decoupled. Wire
the new env vars, builder test coverage, and Helm values.

Signed-off-by: Émile Ré <emile@probo.com>

pkg/proboctl/commontrackerpattern/reenrich.go

@@ -132,7 +132,7 @@ func newCmdReenrich(f *cmdutil.Factory) *cobra.Command {
 			return nil
 		}
 
-		cfg, err := f.TrackerAgentsConfig()
+		enrichmentCfg, mappingCfg, err := f.TrackerAgentsConfig()
 		if err != nil {
 			return err
 		}
@@ -142,7 +142,7 @@ func newCmdReenrich(f *cmdutil.Factory) *cobra.Command {
 			log.WithOutput(f.IOStreams.ErrOut),
 		)
 
-		enricher := cookiebanner.NewCommonPatternEnricher(pgClient, logger, cfg)
+		enricher := cookiebanner.NewCommonPatternEnricher(pgClient, logger, enrichmentCfg, mappingCfg)
 
 		enriched, err := enricher.EnrichByIDs(ctx, ids, flagConcurrency)