feat: surface NPD Tooling in the Project Connections tab

[Guru107]

Follow-up to #9 (merged). Adds the NPD Tooling connection to the Project form's Connections tab.

Approach

Adds a custom DocType Link on Project (the declarative, UI-visible Frappe mechanism for Connections) rather than a dashboard hook:

• Created idempotently in install/after_install.py (add_project_tooling_connection), removed in before_uninstall.py (remove_project_tooling_connection). This matches the app's existing pattern — all its Project customizations are code in after_install.
• NPD Tooling.project matches the Project dashboard's default fieldname, so the connection count resolves automatically.
• Re-asserted by an after_migrate hook on every bench migrate, which is what actually makes the connection durable — see below.

Durability: why after_migrate and not a patch

custom=1 only protects a DocType Link from Customize Form rewrites. It does not survive a doctype re-import: whenever project.json changes (any ERPNext upgrade touching Project), Frappe reloads it via import_file.delete_old_doc → delete_doc(..., for_reload=True) → delete_from_table, which drops every DocType Link row parented to Project, custom ones included. Ordinary migrates skip the re-import on a hash match, which is why a naive "created → migrated → still there" check passes.

A one-shot patch cannot recover from this — once it is in the Patch Log it never runs again, so the connection would be gone permanently. install/after_migrate.py re-runs the idempotent helper after every migrate instead (it runs after doctype sync and after patches, so it sees the post-reload state).

Verified on a site whose Patch Log already contained the earlier one-shot patch: deleted the link, ran bench migrate, and the connection was re-created and present in get_meta("Project").get_dashboard_data().

Idempotency

The guard matches on parent + link_doctype only — it deliberately does not pin custom=1. A site that carries the same connection as a standard (custom=0) row via fixtures or export-customizations would otherwise get a second link and list NPD Tooling twice in Connections. Uninstall is the mirror image: it deletes only the custom=1 rows this app creates, leaving a standard link the app did not put there alone.

The link's identity is spelled once, as PROJECT_TOOLING_LINK in install/after_install.py, and shared by the install guard, the uninstall cleanup and the tests, so the three cannot drift apart.

Why not override_doctype_dashboards / export-customizations

• The dashboard hook works but is code-only and heavier than a one-line connection.
• bench export-customizations for Project bundles all of Project's standard links (Task, Timesheet, …) and every property setter on the site — not clean to ship. The programmatic custom link avoids that and stays consistent with the app.

Files

• install/after_install.py — PROJECT_TOOLING_LINK + add_project_tooling_connection (idempotent), called from after_install
• install/after_migrate.py — new; re-asserts the connection on every migrate
• hooks.py — registers after_migrate; override_doctype_dashboards left commented (unused)
• uninstall/before_uninstall.py — remove_project_tooling_connection removes the custom link on uninstall
• tests/test_npd_tooling.py — asserts the link surfaces in Project's dashboard data + idempotency, and cleans up after itself so it leaves no DocType Link on the core Project doctype

No patch and no patches.txt change: the after_migrate hook covers existing sites, and fresh installs get the connection from after_install.

Verification

• Connection present in frappe.get_meta("Project").get_dashboard_data().
• Deleted the link on a site with the old patch already logged → bench migrate → connection restored (see Durability above).
• Full app suite 72/72 on v15; pre-commit run --all-files → exit 0. (The earlier revision of this branch was also verified 72/72 on v16; the post-review state has only been re-run on v15.)

Note: on each site the connection appears once the app's hooks apply — bench --site <site> migrate, which runs patches and the after_migrate hook. bench migrate does not run after_install; only a fresh install-app does.