feat(doctor): add fn doctor CLI + 14 functions for system management

Adds `fn doctor` read-only diagnostic command with subcommands artefacts,
services, sync, uses-functions, unused, and --json flag for agents.
Each subcommand wraps a registry function in functions/infra/.

New functions:
- artefact_doctor, services_status, pc_locations_drift,
  audit_uses_functions, find_unused_functions (Go diagnostics)
- backup_sqlite_db, rotate_backups, wait_for_http, wait_for_port,
  port_kill, tail_journal, pre_commit_hook_install (bash utilities)
- notify_telegram (Go HTTP)
- backup_all pipeline (tag launcher)

Plus prior session leftovers (scan_secrets_in_dirty, append_diary_entry,
git utilities, http_session_cookie_middleware, compile/full-git pipelines).

Fixes pc_locations_drift filepath.Join bug with absolute dir_path.
Documents fn doctor in CLAUDE.md, .claude/rules/fn_doctor.md (rule 23),
docs/architecture.md, CHANGELOG.md (2026-05-07), and diary entry.

First fn doctor uses-functions run found drift in 7/12 apps (deuda
para sincronizar app.md con imports reales).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

bash/functions/infra/git_auto_commit_dirty.md

@@ -0,0 +1,61 @@
+---
+name: git_auto_commit_dirty
+kind: function
+lang: bash
+domain: infra
+version: "1.0.0"
+purity: impure
+signature: "git_auto_commit_dirty(repo_dir: string, message?: string) -> stdout: commit subject or empty"
+description: "Si el repo tiene cambios sin commitear, hace git add -A y git commit. Genera mensaje automatico si no se pasa: detecta patron de dominio (python/functions/<dom>/, dev/issues/, functions/<dom>/, bash/functions/<dom>/) o usa chore: auto-commit con lista de paths. Anade Co-Authored-By Claude. Salta si el repo es ~/.password-store."
+tags: [git, commit, auto, infra, dirty]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: []
+params:
+  - name: repo_dir
+    desc: "path al repo git donde commitear; default '.'"
+  - name: message
+    desc: "mensaje de commit fijo (opcional); si se omite, se genera automaticamente segun los archivos cambiados"
+output: "subject del commit creado por stdout (primera linea del mensaje); vacio si no habia cambios o si el repo es password-store"
+tested: false
+tests: []
+test_file_path: ""
+file_path: "bash/functions/infra/git_auto_commit_dirty.sh"
+---
+
+## Ejemplo
+
+```bash
+source bash/functions/infra/git_auto_commit_dirty.sh
+
+# Commitear con mensaje automatico
+subject=$(git_auto_commit_dirty /home/lucas/fn_registry)
+echo "Commit: $subject"
+
+# Commitear con mensaje fijo
+git_auto_commit_dirty /home/lucas/myapp "feat: add new feature"
+
+# Revisar si se creo commit (subject no vacio = commit creado)
+if [[ -n "$subject" ]]; then
+    echo "Commit creado: $subject"
+else
+    echo "Sin cambios"
+fi
+```
+
+## Logica de mensaje automatico
+
+| Patron | Mensaje generado |
+|---|---|
+| Todos los paths bajo `python/functions/<dom>/` | `feat(<dom>): auto-commit con N cambios` |
+| Todos los paths bajo `dev/issues/` | `chore(issues): auto-commit` |
+| Todos los paths bajo `functions/<dom>/` | `feat(<dom>): auto-commit con N cambios` |
+| Todos los paths bajo `bash/functions/<dom>/` | `feat(<dom>): auto-commit con N cambios` |
+| Paths dispersos | `chore: auto-commit (N archivos)` + lista |
+
+## Notas
+
+El Co-Authored-By se anade siempre como segundo `-m` del commit. El repo `~/.password-store` (o `$PASSWORD_STORE_DIR`) se salta silenciosamente — `pass` gestiona sus propios commits. Exit 1 solo si el repo no existe o si git commit falla.