plans: tick Phase 1 float expr, add progress log to tcl-sx-completion

plans/tcl-sx-completion.md

@@ -29,12 +29,12 @@ Several apparent gaps are already solved in SX:
 
 Everything here is pure Tcl implementation work.
 
-| Work | Effort | Unlocks in Tcl |
-|---|---|---|
-| Float in `expr` — detect `.` in number tokens, route through float ops instead of `parse-int` | half day | `expr {3.14 * 2}`, `expr {sqrt(2.0)}`, float comparisons |
-| `regexp pattern str` and `regsub pattern str repl` wrapping existing SX primitives | few hours | pattern matching, text processing |
-| `apply {args body} ?arg…?` — anonymous proc call | 1 hour | higher-order functions, `lmap` idiom |
-| `array get/set/names/size/exists/unset` commands | half day | array variables (tokenizer already parses `$arr(key)`) |
+| Status | Work | Effort | Unlocks in Tcl |
+|---|---|---|---|
+| [x] | Float in `expr` — detect `.` in number tokens, route through float ops instead of `parse-int` | half day | `expr {3.14 * 2}`, `expr {sqrt(2.0)}`, float comparisons |
+| [ ] | `regexp pattern str` and `regsub pattern str repl` wrapping existing SX primitives | few hours | pattern matching, text processing |
+| [ ] | `apply {args body} ?arg…?` — anonymous proc call | 1 hour | higher-order functions, `lmap` idiom |
+| [ ] | `array get/set/names/size/exists/unset` commands | half day | array variables (tokenizer already parses `$arr(key)`) |
 
 **Total: ~2 days. Zero SX changes.**
 
@@ -137,6 +137,14 @@ becomes a lasting SX contribution used by every future hosted language.
 
 ---
 
+## Progress log
+
+_Newest first._
+
+- 2026-05-06: Phase 1 float expr — `tcl-num-float?`, `tcl-parse-num`, float-aware `tcl-apply-binop`/`tcl-apply-func`/unary-minus/`**`; `sqrt`/`floor`/`ceil`/`round`/`sin`/`cos`/`tan`/`pow`/`exp`/`log` all float-native; 329/329 tests green
+
+---
+
 ## What stays out of scope
 
 - `package require` of binary loadables