Refactor/better parsing

[devoreofox]

Brace conditionals + block-tree rewrite (v2.0.0.0)

Replaces the old :if/:else/:endif sigil conditionals with brace blocks and reworks the execution model to match. This is a breaking syntax change (existing aliases are migrated automatically on load), so it bumps to 2.0.0.0.

Syntax

• Conditionals are now if (condition) { … }, with else { and else if (condition) { on their own lines (Allman style).
• New else if for chained conditions (first true branch wins), and a new :return statement that halts the whole alias (early exit / guard).
• :set/:wait/:until stay as : statements. The rule is now: sigil = single-line statement, braces = block.

Architecture

• New BlockParser parses an alias into a small node tree (LineNode / IfNode / Branch) and returns structural Diagnostics (unclosed/extra braces, orphan else, bad conditions) with line numbers.
• CommandHandler.ExecuteAsync parses to the tree and walks it recursively instead of the old streaming BlockInterpreter stack. The active-branch bookkeeping is gone (only taken branches are visited); :return unwinds the recursion.
• BlockInterpreter is reduced to static line helpers; the If/Else/EndIf BlockKind cases and the instance stack + Block class are removed. Condition parsing is non-throwing throughout (Condition.TryParse).

Editor / validation

• ValidateBlocks now delegates to BlockParser, so brace/paren/condition errors surface in the editor.
• New trigger validation (empty trigger, spaces, slashes, reserved names).
• Errors render as editor error markers (line highlight + hover tooltip) driven by the diagnostics; the panel above the editor now shows only the line-less ones (trigger, cycle).
• Highlighter colors if/else if/else/:return, reds bad conditions and malformed brace heads, and leaves the braces and parens uncolored.
• List view removed — the syntax-highlighted multiline editor is the only editor now (the MultilineCommands toggle and CommandEntry.Delete go with it). DalamudTextEdit submodule bumped for Tab / Shift+Tab indent and dedent.

Migration (config v2 → v3)

• Rewrites :if X → if (X) {, :else → } + else {, :endif → }, wrapping conditions in parens and re-indenting by nesting depth. A backup is saved first (Silkstring.v2.backup.json). Only touches aliases containing the old sigils; brace aliases are left untouched, so it's safe to re-run.

Tests

• New BlockParserTests (tree shapes + every diagnostic) and ConfigMigratorTests (if/else/endif, nested, passthrough). AliasValidatorTests and BlockInterpreterTests updated for the new syntax and trigger checks.

Docs

• CHANGELOG v2.0.0.0, README (conditionals, editor, settings), and the Help window's Conditionals and Editor tabs all updated to the brace syntax.