fix(session-handoff): hook command literal path [v0.3.3]

PostToolUse hook in `~/.claude/settings.json` was using
`$env:USERPROFILE` (PowerShell syntax), but Claude Code on
Windows runs hook commands through git-bash. Bash treats `$env`
as an empty variable, leaving `":USERPROFILE\..."` as the literal
`-File` argument — PowerShell fails with "invalid filename
format" and the hook never fires.

Install snippet in hooks/README.md now uses literal absolute
path `C:\Users\<you>\.claude\...` with a "Why literal path"
section explaining why `$env:VAR` / `%VAR%` / `~` all break
through the bash-harness chain on Windows.

Retracts the v0.3.0 "live-hook e2e smoke done" closure — that
result was from synthetic replay through the PowerShell tool,
which bypassed the broken harness chain. Real e2e verification
requires this fix plus a CC restart, then a substantive commit
to observe `additionalContext` surface.

skills/session-handoff/SKILL.md

@@ -1,6 +1,6 @@
 ---
 name: session-handoff
-version: 0.3.2
+version: 0.3.3
 description: "Sliding handoff between CC sessions via .tasks/NEXT_SESSION.md. Read on session start: orient agent, ask user before action. Write on session-end phrase or substantive commit. Session-end phrases: «завершаем сессию», «сворачиваемся», «закругляемся», «wrap up session», «end session», «we're done for now». Trigger-line in CLAUDE.md: `session handoff: read on start, write on end`. Skip task-zone phrases: «закрываем эту таску», «pause», «отбой», «разбегаемся»."
 ---