fix(cli): name SIM_CONFIG_DIR in help, and fix the similarity score width (#6795)

Two loose ends from the command-surface audit.

`--help` stated where the profile files live and named only `~/.sim`, so it
was wrong for anyone who had set `SIM_CONFIG_DIR` — which every CI job
pointing the CLI at a scratch directory has. The variable is documented in
the README and the guides; help was the one place that omitted it.

`knowledge search` printed the raw similarity double, `0.2818957269585687`:
a nineteen-character column whose last dozen digits cannot separate one
result from another. A `score` format fixes it to four decimals, the width
`cost` already uses, so the column stays put down the page. `json` and
`yaml` still carry the full double, which is what a script compares.

packages/sim-cli/src/contract/commands.test.ts

@@ -4,6 +4,7 @@
 import type { Command } from 'commander'
 import { describe, expect, it } from 'vitest'
 import { V2_OPERATIONS, type V2OperationName } from '../generated/v2-api'
+import { HELP_EPILOGUE } from '../program'
 import { buildGeneratedCommands } from '../runtime/build'
 import { flagNameFor, flagSpecFor } from '../runtime/request'
 import type { OperationSpec } from '../runtime/types'
@@ -193,4 +194,12 @@ describe('folder-path fields', () => {
     expect(paths).toContain('serviceId')
     expect(paths).toContain('providerId')
   })
+
+  it('mentions the variable that moves the profile files, since help names a path', () => {
+    // The epilogue states where the files live, and SIM_CONFIG_DIR moves both.
+    // Naming only ~/.sim made help wrong for anyone who had set it — including
+    // every CI job that points the CLI at a scratch directory.
+    expect(HELP_EPILOGUE).toContain('~/.sim/config')
+    expect(HELP_EPILOGUE).toContain('SIM_CONFIG_DIR')
+  })
 })

packages/sim-cli/src/contract/commands.ts

@@ -259,7 +259,7 @@ export const CLI_CONTRACT: CliContract = {
     },
     itemsPath: 'results',
     columns: [
-      { header: 'score', path: 'similarity' },
+      { header: 'score', path: 'similarity', format: 'score' },
       { header: 'document', path: 'documentName' },
       { header: 'chunk', path: 'chunkIndex' },
       { header: 'content' },

packages/sim-cli/src/contract/types.ts

@@ -123,6 +123,10 @@ export interface ColumnSpec {
    * wire encoding for the human formats, so a folder no longer prints as
    * `/cli-test-a/nested%20one` in the same row as the `nested one` the server
    * put in the adjacent name column.
+   *
+   * `score` fixes a similarity to four decimals. The raw double arrives as
+   * `0.2818957269585687`, a nineteen-character column whose last dozen digits
+   * cannot separate one result from another.
    */
   format?:
     | 'auto'
@@ -134,6 +138,7 @@ export interface ColumnSpec {
     | 'count'
     | 'trace-count'
     | 'folder-path'
+    | 'score'
 }
 
 export interface BodyVariantSpec {

packages/sim-cli/src/program.ts

@@ -13,7 +13,8 @@ export const PROGRAM_DESCRIPTION = 'Talk to the Sim API from your terminal'
 
 export const HELP_EPILOGUE = `
 Profiles work like the AWS CLI: settings live in ~/.sim/config, keys in
-~/.sim/credentials (0600). Select one with -P, --profile, or SIM_PROFILE.
+~/.sim/credentials (0600), or under SIM_CONFIG_DIR when it is set. Select one
+with -P, --profile, or SIM_PROFILE.
 
 Examples:
   $ sim login                                    Authorize the default profile

packages/sim-cli/src/runtime/build.test.ts

@@ -881,7 +881,9 @@ describe('contract-selected list rendering', () => {
       totalResults: 1,
     })
 
-    expect(printed).toEqual(['0.91\tpolicy.md\t2\tRefunds are available for 30 days.'])
+    // Four decimals, fixed, like the `cost` column: a similarity is compared
+    // against its neighbours, so the width has to stay put down the column.
+    expect(printed).toEqual(['0.9100\tpolicy.md\t2\tRefunds are available for 30 days.'])
   })
 
   it('renders row matches as rows', async () => {

packages/sim-cli/src/runtime/result.test.ts

@@ -172,6 +172,29 @@ describe('a declared field that the API stops returning', () => {
   })
 })
 
+describe('a similarity score, at a width a person can read', () => {
+  const results = {
+    results: [
+      { similarity: 0.2818957269585687, documentName: 'a.md', chunkIndex: 0, content: 'x' },
+    ],
+  }
+  const spec = CLI_CONTRACT.searchKnowledge as CommandSpec
+
+  it('fixes the score to four decimals in the table', () => {
+    // The raw double is nineteen characters wide and its last dozen digits
+    // separate nothing: every row shares them to within a rounding error.
+    renderResult('searchKnowledge', 'table', results, spec)
+    const [, row] = tableLines()
+    expect(row).toContain('0.2819')
+    expect(row).not.toContain('0.2818957269585687')
+  })
+
+  it('leaves the full double in json, which is what a script compares', () => {
+    renderResult('searchKnowledge', 'json', results, spec)
+    expect(JSON.parse(logged[0]).results[0].similarity).toBe(0.2818957269585687)
+  })
+})
+
 describe('folder paths are shown by name, but piped in wire form', () => {
   const folders = [
     {

packages/sim-cli/src/runtime/result.ts

@@ -80,6 +80,8 @@ function renderCell(
       return bool(value as boolean | null)
     case 'cost':
       return typeof value === 'number' ? `$${value.toFixed(4)}` : text(null)
+    case 'score':
+      return typeof value === 'number' ? value.toFixed(4) : text(null)
     case 'count':
       return Array.isArray(value) ? String(value.length) : text(null)
     case 'folder-path':