chore(meta): install pql replication hooks and cover the format marker

This repo had no .pql/hooks/ at all — the four replication hooks were
never installed, because pql's installer used to ignore a redirected
core.hooksPath. It works with .config/hooks now, so init prepends a
two-line shim to each hook that sources the pql half. Existing hook
bodies are untouched; the shim goes above them.

What this buys: post-merge now runs `pql plan upgrade`, so a pull that
brings in a newer changelog format migrates it forward automatically
instead of replaying under superseded rules.

.gitattributes gains a rule for changelog files at the root of
.pql/changelog/. The existing `**/*.sql` pattern requires a directory
component and so did not match the new 0000-format.sql marker, which
would have made it a merge conflict rather than a union merge.

Note for a follow-up: the hand-folded pql block in .config/hooks/post-merge
(lines ~10-12) is now redundant with the shim, so plan import and
decisions sync each run twice per pull. Both are idempotent, so this is
waste rather than breakage — but that block and its stale "installer is
dead" comment can be dropped.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

.config/hooks/post-checkout

@@ -1,4 +1,6 @@
 #!/usr/bin/env bash
+# pql: source .pql/hooks/post-checkout
+_pql_hook="$(git rev-parse --show-toplevel)/.pql/hooks/post-checkout"; [ -f "$_pql_hook" ] && . "$_pql_hook"
 # Post-checkout hook. Folds in pql's planning logic (its .pql/hooks installer is
 # dead under core.hooksPath=.config/hooks).
 #

.config/hooks/post-merge

@@ -1,4 +1,6 @@
 #!/usr/bin/env bash
+# pql: source .pql/hooks/post-merge
+_pql_hook="$(git rev-parse --show-toplevel)/.pql/hooks/post-merge"; [ -f "$_pql_hook" ] && . "$_pql_hook"
 # Post-merge hook (also fires after `git pull`). Folds in pql's planning logic;
 # pql's own .pql/hooks installer is dead under core.hooksPath=.config/hooks.
 #

.config/hooks/post-rewrite

@@ -1,4 +1,6 @@
 #!/usr/bin/env bash
+# pql: source .pql/hooks/post-rewrite
+_pql_hook="$(git rev-parse --show-toplevel)/.pql/hooks/post-rewrite"; [ -f "$_pql_hook" ] && . "$_pql_hook"
 # Post-rewrite hook (fires after `git rebase` / `git commit --amend`). Folds in
 # pql's planning logic; its .pql/hooks installer is dead under
 # core.hooksPath=.config/hooks.

.config/hooks/pre-commit

@@ -1,4 +1,6 @@
 #!/usr/bin/env bash
+# pql: source .pql/hooks/pre-commit
+_pql_hook="$(git rev-parse --show-toplevel)/.pql/hooks/pre-commit"; [ -f "$_pql_hook" ] && . "$_pql_hook"
 # Pre-commit hook dispatcher. Runs modular checks from tooling/.
 # Installed via: git config core.hooksPath .config/hooks
 set -euo pipefail

.gitattributes

@@ -1 +1,2 @@
 .pql/changelog/**/*.sql merge=union
+.pql/changelog/*.sql merge=union

.gitignore

@@ -126,3 +126,5 @@ client/settings.db-shm
 client/settings.db-wal
 
 .claude/settings.local.json
+.pql/*
+!.pql/changelog/