v0.3.5

v0.3.5 — the companion skill installs itself

The dsx companion skill (the one that teaches droids to mine their own
session history) now ships inside the binary. Installing or updating dsx via
install.sh offers to install it; previously the only way to get the skill
was cloning the repo and symlinking .agents/skills/dsx by hand.

New: dsx skill sync

dsx skill sync                         # (re)answer the questionnaire
dsx skill sync --to ~/.agents/skills   # pick target dir(s) directly
dsx skill sync --apply                 # reapply your saved choice (what install.sh runs)

• The questionnaire offers ~/.agents/skills/dsx (default yes) and
  ~/.factory/skills/dsx (default no). Your answers are cached at
  $XDG_DATA_HOME/dsx/skill-prefs.json, so installer re-runs refresh the
  skill silently instead of re-asking. Bare dsx skill sync always re-asks,
  with your cached answers as the defaults.
• Declining is remembered too, and removes any previously installed copies;
  so does deselecting one directory.
• Without a terminal (agent-driven installs, CI), nothing prompts, hangs, or
  fails: dsx applies your saved choice, or on first run installs the default
  (~/.agents/skills/dsx) and prints a line saying so.

Behavior changes

• install.sh now runs dsx skill sync --apply after installing the binary.
  Existing users see the questionnaire once on their next update, then never
  again unless they run dsx skill sync themselves.
• If you previously symlinked the skill from a clone, accepting that
  directory replaces the symlink with a real copy (version-locked to the
  binary); the clone itself is untouched.
• The skill is embedded at build time from .agents/skills/dsx/, the same
  source as the dsx ask / dsx insights --deep sub-droid cheatsheet, so
  installed skill and binary can never drift apart.

Verification

• 48 tests (8 new covering skill write/overwrite, symlink replacement,
  deselection cleanup, prefs round-trip), typecheck, SEA smoke tests on
  linux-x64: interactive questionnaire over /dev/tty, silent --apply
  re-runs, no-tty defaulting, decline-removes-copy.

Caveat: a harness that allocates a pty for shell commands is
indistinguishable from a human terminal, so a first-time install there still
shows the questionnaire.