docs: fix MD010 hard-tabs in go-test output blocks

CI's markdown-lint check (markdownlint-cli2 v0.13.0) flagged literal
tabs from captured `go test` output inside fenced code blocks in the
three worked examples. Replace tabs with spaces; visual alignment is
preserved, content is unchanged.

Co-Authored-By: Paperclip <[email protected]>

Author: LeadGoEngineer

docs/example-crono.md

@@ -183,8 +183,8 @@ EXPORT_CLI_BIN=/tmp/crono-export go test -tags=compat ./...
 **Expected:**
 
 ```
-ok  	github.com/quantcli/crono-export-cli	0.010s
-ok  	github.com/quantcli/crono-export-cli/cmd	0.005s
+ok      github.com/quantcli/crono-export-cli    0.010s
+ok      github.com/quantcli/crono-export-cli/cmd    0.005s
 ...
 ```
 

docs/example-liftoff.md

@@ -164,7 +164,7 @@ LIFTOFF_EXPORT_BIN=/tmp/liftoff-export go test -tags=compat ./...
 **Expected:**
 
 ```
-ok  	github.com/quantcli/liftoff-export-cli	0.003s
+ok      github.com/quantcli/liftoff-export-cli    0.003s
 ```
 
 The `compat` suite covers CONTRACT.md §4 parse-level conformance (the `--format` flag, `UnknownFormatFails`, `FlagValidationIsHermetic`) across all four data-producing subcommands (`workouts list`, `workouts stats`, `bodyweights list`, `bodyweights stats`). Data-path subtests (`--format json` with live data) are skipped because the suite does not provision a Liftoff OAuth token; the parse-level subtests run without credentials.

docs/example-withings.md

@@ -196,8 +196,8 @@ WITHINGS_EXPORT_BIN=/tmp/withings-export go test -tags=compat ./...
 **Expected:**
 
 ```
-ok  	github.com/quantcli/withings-export-cli	0.003s
-ok  	github.com/quantcli/withings-export-cli/internal/auth	0.003s
+ok      github.com/quantcli/withings-export-cli    0.003s
+ok      github.com/quantcli/withings-export-cli/internal/auth    0.003s
 ```
 
 The suite covers CONTRACT.md §4 (format flag surface, `--format json` returns a JSON array, `--format csv` returns a header row, default equals `--format markdown`) and §7 (hermeticity) across all five data subcommands. All cells in the CONTRACT.md Status table for `withings-export` are **machine**-attested.