docs: fix redirect chains and disambiguate duplicate titles

Redirects:
- /cron now goes directly to /automation/cron-jobs (was chaining via /cron-jobs)
- /model and /model/ now go directly to /concepts/models (was chaining via /models)

Duplicate titles disambiguated (6 of 7 - Logging is orphaned):
- Health Checks (macOS), Skills (macOS), Voice Wake (macOS), WebChat (macOS)
- General Troubleshooting (help/ vs gateway/)
- Provider Directory (providers/index vs concepts/model-providers)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/platforms/mac/health.md

@@ -2,7 +2,7 @@
 summary: "How the macOS app reports gateway/Baileys health states"
 read_when:
   - Debugging mac app health indicators
-title: "Health Checks"
+title: "Health Checks (macOS)"
 ---
 
 # Health Checks on macOS

docs/platforms/mac/skills.md

@@ -3,7 +3,7 @@ summary: "macOS Skills settings UI and gateway-backed status"
 read_when:
   - Updating the macOS Skills settings UI
   - Changing skills gating or install behavior
-title: "Skills"
+title: "Skills (macOS)"
 ---
 
 # Skills (macOS)

docs/platforms/mac/voicewake.md

@@ -2,7 +2,7 @@
 summary: "Voice wake and push-to-talk modes plus routing details in the mac app"
 read_when:
   - Working on voice wake or PTT pathways
-title: "Voice Wake"
+title: "Voice Wake (macOS)"
 ---
 
 # Voice Wake & Push-to-Talk

docs/platforms/mac/webchat.md

@@ -2,7 +2,7 @@
 summary: "How the mac app embeds the gateway WebChat and how to debug it"
 read_when:
   - Debugging mac WebChat view or loopback port
-title: "WebChat"
+title: "WebChat (macOS)"
 ---
 
 # WebChat (macOS app)