feat(lsp): implement get_hover and get_definitions for LSP runtime (#1240)

Add hover and definition support to LspClient and LspRuntime.

- LspClient.get_hover(): sends textDocument/hover, returns Hover dict or None
- LspClient.get_definitions(): sends textDocument/definition, handles
  Location, Location[], and LocationLink[] responses
- LspRuntime wrappers: input validation, file reading, language
  detection, 1-based to 0-based line/column conversion
- try/finally for did_close() safety on both new methods
- Tool adapter: HOVER and DEFINITIONS dispatch to runtime instead of
  raising LspNotAvailableError
- Updated lsp_tool_adapter_coverage test (HOVER -> REFERENCES)
- 21 Behave BDD scenarios with full path coverage

Closes #1243

Co-authored-by: Hamza Khyari <hamza.khyari@cleverthis.com>
Co-committed-by: Hamza Khyari <hamza.khyari@cleverthis.com>

features/lsp_hover_definitions.feature

@@ -0,0 +1,94 @@
+@lsp-hover-definitions
+Feature: LSP hover and definitions methods
+  Verifies that LspClient and LspRuntime implement get_hover
+  and get_definitions with full path coverage.
+
+  # ── LspClient method existence ─────────────────────────
+
+  Scenario: LspClient has get_hover method for lsp_hd
+    Then LspClient should have a "get_hover" method for lsp_hd
+
+  Scenario: LspClient has get_definitions method for lsp_hd
+    Then LspClient should have a "get_definitions" method for lsp_hd
+
+  # ── LspClient get_hover paths ──────────────────────────
+
+  Scenario: LspClient get_hover returns dict result for lsp_hd
+    When I call LspClient.get_hover with mock returning a dict for lsp_hd
+    Then the hover result should be a dict for lsp_hd
+
+  Scenario: LspClient get_hover returns None when server returns null for lsp_hd
+    When I call LspClient.get_hover with mock returning null for lsp_hd
+    Then the hover result should be None for lsp_hd
+
+  Scenario: LspClient get_hover returns None for unexpected type for lsp_hd
+    When I call LspClient.get_hover with mock returning an integer for lsp_hd
+    Then the hover result should be None for lsp_hd
+
+  # ── LspClient get_definitions paths ────────────────────
+
+  Scenario: LspClient get_definitions returns list of Locations for lsp_hd
+    When I call LspClient.get_definitions with mock returning a list for lsp_hd
+    Then the definitions result should be a list with 1 item for lsp_hd
+
+  Scenario: LspClient get_definitions wraps single Location in list for lsp_hd
+    When I call LspClient.get_definitions with mock returning a single dict for lsp_hd
+    Then the definitions result should be a list with 1 item for lsp_hd
+
+  Scenario: LspClient get_definitions returns empty list for null for lsp_hd
+    When I call LspClient.get_definitions with mock returning null for lsp_hd
+    Then the definitions result should be an empty list for lsp_hd
+
+  Scenario: LspClient get_definitions returns empty for unexpected type for lsp_hd
+    When I call LspClient.get_definitions with mock returning an integer for lsp_hd
+    Then the definitions result should be an empty list for lsp_hd
+
+  # ── LspRuntime method existence ────────────────────────
+
+  Scenario: LspRuntime has get_hover method for lsp_hd
+    Then LspRuntime should have a "get_hover" method for lsp_hd
+
+  Scenario: LspRuntime has get_definitions method for lsp_hd
+    Then LspRuntime should have a "get_definitions" method for lsp_hd
+
+  # ── LspRuntime input validation ────────────────────────
+
+  Scenario: LspRuntime get_hover rejects empty name for lsp_hd
+    When I call LspRuntime.get_hover with empty name for lsp_hd
+    Then a ValueError should be raised for lsp_hd with message "name"
+
+  Scenario: LspRuntime get_hover rejects empty file_path for lsp_hd
+    When I call LspRuntime.get_hover with empty file_path for lsp_hd
+    Then a ValueError should be raised for lsp_hd with message "file_path"
+
+  Scenario: LspRuntime get_hover rejects line 0 for lsp_hd
+    When I call LspRuntime.get_hover with line 0 for lsp_hd
+    Then a ValueError should be raised for lsp_hd with message "line"
+
+  Scenario: LspRuntime get_hover rejects column 0 for lsp_hd
+    When I call LspRuntime.get_hover with column 0 for lsp_hd
+    Then a ValueError should be raised for lsp_hd with message "column"
+
+  Scenario: LspRuntime get_definitions rejects empty name for lsp_hd
+    When I call LspRuntime.get_definitions with empty name for lsp_hd
+    Then a ValueError should be raised for lsp_hd with message "name"
+
+  Scenario: LspRuntime get_definitions rejects empty file_path for lsp_hd
+    When I call LspRuntime.get_definitions with empty file_path for lsp_hd
+    Then a ValueError should be raised for lsp_hd with message "file_path"
+
+  Scenario: LspRuntime get_definitions rejects line 0 for lsp_hd
+    When I call LspRuntime.get_definitions with line 0 for lsp_hd
+    Then a ValueError should be raised for lsp_hd with message "line"
+
+  Scenario: LspRuntime get_definitions rejects column 0 for lsp_hd
+    When I call LspRuntime.get_definitions with column 0 for lsp_hd
+    Then a ValueError should be raised for lsp_hd with message "column"
+
+  # ── Tool adapter wiring ────────────────────────────────
+
+  Scenario: Tool adapter maps HOVER capability for lsp_hd
+    Then the tool adapter capability map should include "hover" for lsp_hd
+
+  Scenario: Tool adapter maps DEFINITIONS capability for lsp_hd
+    Then the tool adapter capability map should include "definitions" for lsp_hd