fix: remove bd sync from polecat startup sequence (gt-aobh)

Polecats share the same beads database at the rig level. The refinery
and witness manage syncing beads. Running bd sync on polecat startup
causes contention when multiple polecats spawn simultaneously and
creates potential race conditions.

This change removes bd sync --from-main from:
- prompts/roles/polecat.md On Startup section
- internal/beads/molecules_session.go orient step
- internal/beads/molecules_work.go orient step
- docs/polecat-wisp-architecture.md load context section

Troubleshooting sections that recommend bd sync --from-main for
recovery scenarios are preserved.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs/polecat-wisp-architecture.md

@@ -146,7 +146,6 @@ Read polecat.md protocol. Understand:
 
 Load context:
 - gt prime
-- bd sync --from-main
 - gt mail inbox
 
 ## Step: handoff-read

internal/beads/molecules_session.go

@@ -456,7 +456,6 @@ Read polecat.md protocol and initialize context.
 
 ` + "```" + `bash
 gt prime               # Load Gas Town context
-bd sync --from-main    # Fresh beads state
 gt mail inbox          # Check for work assignment
 ` + "```" + `
 

internal/beads/molecules_work.go

@@ -287,7 +287,6 @@ Load context and check for interrupts.
 
 ` + "```" + `bash
 gt prime                    # Load Gas Town context
-bd sync --from-main         # Fresh beads state
 ` + "```" + `
 
 Check for:

prompts/roles/polecat.md

@@ -144,8 +144,7 @@ Gas Town has TWO beads databases:
 
 ### On Startup
 ```bash
-bd sync --from-main    # Pull latest beads state
+bd show <your-issue>   # Verify your assignment (beads synced by refinery/witness)
-bd show <your-issue>   # Verify your assignment
 ```
 
 ### During Work