…e blocks dead code

Bash performs tilde expansion only when `~` is UNQUOTED. Inside double quotes
it is a literal character, so `"~/.claude/skills/gstack/bin/x"` is a relative
path that never resolves. Two preamble generators interpolated a tilde-based
`ctx.paths.binDir` inside double quotes:

  scripts/resolvers/preamble/generate-brain-sync-block.ts   (4 sites)
  scripts/resolvers/preamble/generate-preamble-bash.ts      (1 site)

Those five sites expanded into ~250 broken lines across 49 generated
SKILL.md files. Concretely:

- `_BRAIN_SYNC_BIN` / `_BRAIN_CONFIG_BIN` never resolved, so the whole
  "Artifacts Sync (skill start)" block was inert. `artifacts_sync_mode`
  always read as "off" regardless of the user's real config, and the
  `--discover-new` / `--once` sync calls always failed (silently, behind
  `|| true`).
- The pending-telemetry finalize guard
  `[ -x "~/.../gstack-telemetry-log" ]` was ALWAYS false, so the event was
  never logged — but the very next line still ran `rm -f "$_PF"`, deleting
  the pending marker. Pending telemetry was discarded unlogged rather than
  being flushed.

Nothing errored, because every call site was guarded by `|| true` or an
`if` that simply never fired. The features looked wired up and did nothing.

Fix: add `quoteSafePath()` in scripts/resolvers/types.ts, which rewrites a
leading `~/` to `$HOME/`, and apply it at exactly the five quoted sites.
Env-var hosts (`$GSTACK_BIN`) already expand correctly when quoted and pass
through untouched. Unquoted interpolations are deliberately left alone —
they expand fine and keep the more readable `~` in generated docs.

The 49 SKILL.md changes in this commit are regenerated output
(`bun run gen:skill-docs`), not hand edits.

Verified:
- `[ -x "~/..." ]` → false, `[ -x "$HOME/..." ]` → true on this machine.
- 0 broken quoted-tilde sites remain in generated docs (was ~250).
- 770 pass / 0 fail across gen-skill-docs (incl. golden fixtures),
  skill-validation, skill-size-budget, brain-sync, brain-sync-windows-paths.
- 64 pass / 0 fail across skill-e2e, autoplan-chain, one-way-doors,
  hook-scripts, question-preference-hook.