fix: DB completion path parsing, array-of-UDT resolution, blink source registration

- Fix path extraction pattern (missing closing quote, extra capture group)
- Add Array[..] of "UdtName" detection for nested member resolution
- Remove vim.schedule_wrap from DB member callback (causes blink.cmp timeout)
- Add built-in instruction parameter fallback (IEC_TIMER IN/PT/Q/ET)
- Ensure DB cache is populated on demand in completion source
- Make try_register() succeed without cmp.add_source_provider API
- docs: add blink.cmp source config steps to installation guide

README.md

@@ -11,7 +11,7 @@ A Neovim/LazyVim plugin that launches the [`tia-lsp`](https://gitea.l-tech.rs/la
 | **Tab Navigation** | Jump between parameters with `<Tab>` in insert mode |
 | **Workspace UDT Scanner** | Scans project for user-defined types (.udt files) |
 | **Workspace Global DB Scanner** | Scans project for global data blocks (.db files) |
-| **blink.cmp Integration** | Smart completion source for blink.cmp |
+| **blink.cmp Integration** | Smart completion source for blink.cmp — DB members, FB parameters, built-in types (IEC_TIMER IN/PT/Q/ET), nested UDT/array-of-UDT path resolution |
 | **Attribute Block Toggle** | Interactive expand/collapse of `{...}` blocks with `<Leader>xa` |
 | **Tree-sitter Highlighting** | Syntax highlighting via tree-sitter queries |
 
@@ -105,7 +105,33 @@ return {
 }
 ```
 
-**Step 5: Verify**
+**Step 5: Configure blink.cmp defaults**
+
+The `scl` completion source must be listed in blink.cmp's `sources.default` with the corresponding provider definition. Create or update your blink.cmp config:
+
+```lua
+-- ~/.config/nvim/lua/plugins/blink.lua (or extend your existing blink.cmp spec)
+return {
+  "saghen/blink.cmp",
+  optional = true,
+  opts = {
+    sources = {
+      default = { "lsp", "path", "snippets", "buffer", "scl" },
+      providers = {
+        scl = {
+          name = "scl",
+          module = "tia.blink_cmp_source",
+          score_offset = 100,
+        },
+      },
+    },
+  },
+}
+```
+
+> **Why this is needed:** blink.cmp only queries sources listed in `sources.default`. Without `"scl"` there, the DB member and built-in type completions (e.g., `"MyDB".myField` or `#myTimer.IN`) will not appear.
+
+**Step 6: Verify**
 
 Open a `.scl` file and run `:LspInfo`. `tia_lsp` should be attached. Run `:checkhealth` for detailed diagnostics.