chore: wire up .beads symlink to dedicated beads-teenyc repo

Issue tracking now lives in spinorml/beads-teenyc instead of being
untracked locally. Removes the .beads exclusion from .gitignore and
.git/info/exclude that dated back to an earlier, abandoned bd setup.

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

Author: arshadm

.beads

@@ -0,0 +1 @@
+../beads-teenyc/.beads

.gitignore

@@ -112,7 +112,6 @@ dialect.rs
 # Beads / Dolt files (added by bd init)
 .dolt/
 *.db
-.beads
 .beads-credential-key
 .scratch/
 agent.log