feat(dap): resolve debug adapters discovery-first

Resolve dap_deps through the shared resolver; adapters self-validate from $PATH
(delve via dlv, codelldb, lldb, python via debugpy) with Mason loaded lazily off
the :Dap tick. Client configs follow the validate-FIRST / raise-LAST contract so
remote-attach adapters stay registered. debugpy resolves via a bounded probe
cascade with a slow-TTL negative cache (no permanent latch). Shared
attach_endpoint validates remote host/port shape at config time (config.port and
opts.default_port to the same 1-65535 contract).

Author: charliie-dev

lua/modules/configs/tool/dap/clients/codelldb.lua

@@ -4,13 +4,18 @@ return function()
 	local utils = require("modules.utils.dap")
 	local is_windows = require("core.global").is_windows
 
+	-- Self-validate at config time (validate FIRST — contract: tool/dap/init.lua
+	-- resolver spec): launch AND attach both spawn the local binary, so
+	-- unlike delve/python nothing is worth registering without it — error if missing.
+	local command =
+		require("modules.utils.tools").exepath_or_error("codelldb", "install it via Mason or your package manager")
 	dap.adapters.codelldb = {
 		type = "server",
 		port = "${port}",
 		executable = {
-			command = vim.fn.exepath("codelldb"), -- Find codelldb on $PATH
+			command = command,
 			args = { "--port", "${port}" },
-			detached = is_windows and false or true,
+			detached = not is_windows,
 		},
 	}
 	dap.configurations.c = {

lua/modules/configs/tool/dap/clients/delve.lua

@@ -1,34 +1,53 @@
--- https://github.com/mfussenegger/nvim-dap/wiki/Debug-Adapter-installation#go
+-- https://github.com/mfussenegger/nvim-dap/wiki/Debug-Adapter-installation#go-using-delve-directly
 -- https://github.com/golang/vscode-go/blob/master/docs/debugging.md
 return function()
 	local dap = require("dap")
 	local utils = require("modules.utils.dap")
+	local is_windows = require("core.global").is_windows
 
-	if not require("mason-registry").is_installed("go-debug-adapter") then
-		vim.notify(
-			"Automatically installing `go-debug-adapter` for go debugging",
-			vim.log.levels.INFO,
-			{ title = "nvim-dap" }
-		)
+	-- Use delve's built-in DAP server (`dlv dap`) directly, no separate go-debug-adapter.
+	-- `dlv` resolves lazily on the spawn path: remote attach needs no local binary, so
+	-- the adapter registers even when it's absent.
 
-		local go_dbg = require("mason-registry").get_package("go-debug-adapter")
-		go_dbg:install():once(
-			"closed",
-			vim.schedule_wrap(function()
-				if go_dbg:is_installed() then
-					vim.notify("Successfully installed `go-debug-adapter`", vim.log.levels.INFO, { title = "nvim-dap" })
-				end
-			end)
-		)
+	---A function adapter (over a static table) so a remote `attach` config can
+	---connect to an already-running `dlv dap` instead of spawning a local one.
+	---@param callback fun(adapter: table)
+	---@param config table
+	local function delve_adapter(callback, config)
+		if config.request == "attach" and config.mode == "remote" then
+			-- Shared shape validation (utils.attach_endpoint): malformed values
+			-- error at config time instead of surfacing as an opaque connection
+			-- failure. Default when unset: 38697 is the conventional example
+			-- port from the nvim-dap wiki, not a delve default.
+			local host, port = utils.attach_endpoint(config, { label = "delve remote attach", default_port = 38697 })
+			callback({
+				type = "server",
+				host = host,
+				port = port,
+			})
+		else
+			-- Resolve lazily so a dlv installed after config load is picked up without reconfiguring.
+			local command = require("modules.utils.tools").exepath_or_error(
+				"dlv",
+				"install delve via Mason or your package manager"
+			)
+			callback({
+				type = "server",
+				port = "${port}",
+				executable = {
+					command = command,
+					args = { "dap", "-l", "127.0.0.1:${port}" },
+					detached = not is_windows,
+				},
+			})
+		end
 	end
 
-	dap.adapters.go = {
-		type = "executable",
-		command = "node",
-		args = {
-			vim.env.MASON .. "/packages/go-debug-adapter" .. "/extension/dist/debugAdapter.js",
-		},
-	}
+	-- Register under both names: the configurations below use `type = "go"`, while
+	-- mason-nvim-dap / other integrations reference the adapter as `delve`.
+	dap.adapters.go = delve_adapter
+	dap.adapters.delve = delve_adapter
+
 	dap.configurations.go = {
 		{
 			type = "go",
@@ -37,7 +56,6 @@ return function()
 			cwd = "${workspaceFolder}",
 			program = utils.input_file_path(),
 			console = "integratedTerminal",
-			dlvToolPath = vim.fn.exepath("dlv"),
 			showLog = true,
 			showRegisters = true,
 			stopOnEntry = false,
@@ -50,7 +68,6 @@ return function()
 			program = utils.input_file_path(),
 			args = utils.input_args(),
 			console = "integratedTerminal",
-			dlvToolPath = vim.fn.exepath("dlv"),
 			showLog = true,
 			showRegisters = true,
 			stopOnEntry = false,
@@ -63,7 +80,6 @@ return function()
 			program = utils.input_exec_path(),
 			args = utils.input_args(),
 			console = "integratedTerminal",
-			dlvToolPath = vim.fn.exepath("dlv"),
 			mode = "exec",
 			showLog = true,
 			showRegisters = true,
@@ -76,7 +92,6 @@ return function()
 			cwd = "${workspaceFolder}",
 			program = utils.input_file_path(),
 			console = "integratedTerminal",
-			dlvToolPath = vim.fn.exepath("dlv"),
 			mode = "test",
 			showLog = true,
 			showRegisters = true,
@@ -89,11 +104,17 @@ return function()
 			cwd = "${workspaceFolder}",
 			program = "./${relativeFileDirname}",
 			console = "integratedTerminal",
-			dlvToolPath = vim.fn.exepath("dlv"),
 			mode = "test",
 			showLog = true,
 			showRegisters = true,
 			stopOnEntry = false,
 		},
 	}
+
+	-- Availability check LAST (contract: tool/dap/init.lua resolver spec); the raise
+	-- is the provisioning signal — the attach-capable adapters above stay registered.
+	require("modules.utils.tools").exepath_or_error(
+		"dlv",
+		"local `dlv dap` launch is unavailable until installed (remote attach still works)"
+	)
 end

lua/modules/configs/tool/dap/clients/lldb.lua

@@ -3,9 +3,19 @@ return function()
 	local dap = require("dap")
 	local utils = require("modules.utils.dap")
 
+	-- Opt-in preset (not in default dap_deps; codelldb covers C-family). Self-validate
+	-- so the resolver surfaces `lldb` (validate FIRST — contract:
+	-- tool/dap/init.lua resolver spec). LLVM 18 renamed `lldb-vscode` ->
+	-- `lldb-dap`; probe the new name first, keep the old for distros still
+	-- shipping it.
+	local command = require("modules.utils.tools").exepath_or_error(
+		{ "lldb-dap", "lldb-vscode" },
+		"install it via your package manager (ships with LLVM/lldb)"
+	)
+
 	dap.adapters.lldb = {
 		type = "executable",
-		command = vim.fn.exepath("lldb-vscode"), -- Find lldb-vscode on $PATH
+		command = command,
 	}
 	dap.configurations.c = {
 		{