Rollback Workspace Manager header attempts and add tool pager

PR Details:
- Restores Workspace Manager layout from the pre-header/banner anchor.
- Removes failed top Workspace Manager header/banner/control experiments.
- Adds centered [PREV] <toolname> [NEXT] above the existing tools/editors section.
- Selects and mounts the first available tool on load.
- Keeps explicit gameId behavior without restoring legacy query fallback.

Author: DavidQ

docs/dev/codex_rules.md

@@ -4,31 +4,48 @@ These rules OVERRIDE all other instructions.
 
 ## This PR
 
-Force the Workspace Manager tool pager UI above Editors.
+Rollback failed Workspace Manager header/banner attempts, then add only the requested pager.
 
 Allowed:
-- targeted Workspace Manager UI/render behavior changes
-- remove newly created top header/banner/control area
+- targeted rollback of Workspace Manager files affected by 20_14 through 20_19
+- add centered [PREV] <toolname> [NEXT] above tools/editors
 - validation report
 
 Forbidden:
 - broad cleanup
 - unrelated refactoring
 - changes to samples behavior
 - changes to required labels
-- new header/banner replacement
+- new header
+- new banner
+- keeping failed top Workspace Manager control/header area
 - second SSoT
 - start_of_day changes
 - roadmap text rewrite outside status markers
 
-## User-Approved Exception
+## Rollback Anchor
+
+Find the commit with comment:
+
+Remove Workspace Manager default and query fallbacks
+
+Use it as the Workspace Manager restore anchor before applying pager.
+
+## Required UI
+
+Restore normal Workspace Manager content first.
+
+Then add only:
+
+[PREV] <toolname> [NEXT]
+
+above the existing tools/editors section.
 
-For this PR only:
-- the first available tool in the game tool list MUST be selected on page load
-- the selected first tool MUST be displayed between PREV and NEXT
-- the selected first tool MAY be activated/mounted on page load
+## User-Approved Behavior
 
-This approved behavior is not considered an anti-pattern in this PR.
+For this PR:
+- first available tool is selected on page load
+- selected tool is active/mounted on page load
 
 ## Still Forbidden
 
@@ -37,21 +54,7 @@ Do not restore:
 - legacy `game` query fallback
 - hidden fallback routing
 - stale memory reuse
-- label-text route guessing
-- DOM-order route guessing
-
-## Required UI
-
-Create centered control directly above Editors:
-
-[PREV] <toolname> [NEXT]
-
-Do not use:
-- detached top banner
-- new header
-- dropdown workflow
-- Select Tool button
-- Mount button for initial flow
+- broken header/banner/control area
 
 ## Anti-Patterns Forbidden
 

docs/dev/reports/workspace_manager_rollback_header_and_tool_pager_validation.md

@@ -0,0 +1,85 @@
+# BUILD_PR_LEVEL_20_20_ROLLBACK_WORKSPACE_HEADER_AND_ADD_TOOL_PAGER Validation
+
+## Rollback Anchor
+- Commit hash: `c64249d281bcd69e60bf58590061627a2b500cd8`
+- Commit comment: `Remove Workspace Manager default and query fallbacks`
+
+## Changed Files
+- `tools/Workspace Manager/index.html`
+- `tools/Workspace Manager/main.js`
+- `tools/Workspace Manager/toolHost.css`
+- `docs/dev/reports/workspace_manager_rollback_header_and_tool_pager_validation.md`
+
+## Proof: Failed Header/Banner/Control Area Removed
+- `index.html` no longer contains `tool-host-surface` or `tool-host-editor-overlay` blocks.
+- `index.html` no longer contains inline boot-fallback script text (`Workspace Manager boot import failed`).
+- Command checks:
+  - `PASS: index.html missing tool-host-surface`
+  - `PASS: index.html missing editor overlay`
+  - `PASS: index.html missing inline boot catch banner script`
+
+## Proof: Normal Workspace Manager Content Loads Below Site Chrome
+- Workspace mount surface remains present and is the primary page body container:
+  - `tools/Workspace Manager/index.html:17` `<div data-tool-host-mount-container class="tool-host-workspace__mount"></div>`
+- Layout keeps mount surface filling remaining page area:
+  - `tools/Workspace Manager/toolHost.css:14` `.tool-host-workspace {`
+  - `tools/Workspace Manager/toolHost.css:15` `display: flex;`
+  - `tools/Workspace Manager/toolHost.css:16` `flex-direction: column;`
+  - `tools/Workspace Manager/toolHost.css:26` `.tool-host-workspace__mount {`
+  - `tools/Workspace Manager/toolHost.css:27` `flex: 1 1 auto;`
+
+## Proof: Only [PREV] <toolname> [NEXT] Was Added
+- Pager markup only:
+  - `tools/Workspace Manager/index.html:11` `<section class="tool-host-pager" ...>`
+  - `tools/Workspace Manager/index.html:12` `[PREV]`
+  - `tools/Workspace Manager/index.html:13` current tool label span
+  - `tools/Workspace Manager/index.html:14` `[NEXT]`
+- No new header/banner block exists in `index.html`.
+
+## Proof: Pager Appears Above Existing Tools/Editors Section
+- Pager block is defined before mount/editors container in DOM:
+  - `tools/Workspace Manager/index.html:11` pager section
+  - `tools/Workspace Manager/index.html:17` mount container
+- Pager is centered:
+  - `tools/Workspace Manager/toolHost.css:31` `.tool-host-pager {`
+  - `tools/Workspace Manager/toolHost.css:35` `justify-content: center;`
+
+## Proof: First Available Tool Selected/Mounted On Load
+- Initial tool selection for explicit game launch context uses first available tool:
+  - `tools/Workspace Manager/main.js:657` `const initialToolId = requestedToolId || (initialGameEntry && gameLaunchRequested ? (toolIds[0] || "") : "");`
+- Selected tool is mounted during init:
+  - `tools/Workspace Manager/main.js:677` `mountSelectedTool("init");`
+
+## Proof: Prev/Next Changes Selected/Mounted Tool
+- Prev handler changes selection and mounts:
+  - `tools/Workspace Manager/main.js:540` prev click binding
+  - `tools/Workspace Manager/main.js:544` `mountSelectedTool("prev");`
+- Next handler changes selection and mounts:
+  - `tools/Workspace Manager/main.js:549` next click binding
+  - `tools/Workspace Manager/main.js:553` `mountSelectedTool("next");`
+
+## Proof: gameId || game Fallback Not Restored
+- `readInitialGameId` uses only `gameId`:
+  - `tools/Workspace Manager/main.js:279` `const gameId = (url.searchParams.get("gameId") || "").trim();`
+- Command checks:
+  - `PASS: main.js missing gameId || game`
+  - `PASS: main.js missing searchParams.get("game")`
+
+## Proof: Samples Remain Untouched
+- Command check:
+  - `PASS: samples untouched in git diff`
+  - Based on `git diff --name-only -- samples games` returning no changed files.
+
+## External Memory / Stale Memory Guard
+- Existing context cleanup remains intact:
+  - `tools/Workspace Manager/main.js:4` imports `removeToolHostSharedContextById`
+  - `tools/Workspace Manager/main.js:347` `unmountGameFrame()` cleanup routine
+  - `tools/Workspace Manager/main.js:622` cleanup bound on `beforeunload`
+
+## Anti-Pattern Self-Check
+- No `gameId || game` fallback restored: PASS
+- No legacy `searchParams.get("game")` fallback: PASS
+- No new header/banner/control area: PASS
+- No dropdown + Select Tool + Mount required for initial flow: PASS (pager-only controls are present)
+- No samples behavior changes: PASS
+- No broad Workspace Manager refactor: PASS (targeted files only)

docs/operations/dev/codex_commands.md

@@ -1,4 +1,4 @@
-# Codex Commands — BUILD_PR_LEVEL_20_19_FORCE_WORKSPACE_TOOL_PAGER_ABOVE_EDITORS
+# Codex Commands — BUILD_PR_LEVEL_20_20_ROLLBACK_WORKSPACE_HEADER_AND_ADD_TOOL_PAGER
 
 ## Model
 GPT-5.4 or GPT-5.3-codex
@@ -10,70 +10,60 @@ High
 
 ```text
 Read docs/dev/codex_rules.md first.
-Read docs/dev/reports/workspace_manager_auto_mount_tool_selection_validation.md if present.
-Read docs/dev/specs/TOOL_LAUNCH_SSOT.md if present.
 
-Execute BUILD_PR_LEVEL_20_19_FORCE_WORKSPACE_TOOL_PAGER_ABOVE_EDITORS.
+Execute BUILD_PR_LEVEL_20_20_ROLLBACK_WORKSPACE_HEADER_AND_ADD_TOOL_PAGER.
 
-User UAT correction:
-- Do not use a new HEADER at all.
-- Delete/remove what was created as the top Workspace Manager header/banner/control area.
-- Force this UI centered above Editors:
-  [PREV] <toolname> [NEXT]
-- On page load, default <toolname> to the first tool in the available list.
-- No more attempts to keep the header.
-- No dropdown + Select Tool + Mount initial workflow.
+User UAT failure:
+- Current Workspace Manager page still has the unwanted header/banner/control area.
+- Only the site image is showing below it.
+- User wants this rolled back to the way Workspace Manager loaded before the failed header attempts.
+- Then add only [PREV] <toolname> [NEXT] above the tools/editors section.
 
-Goal:
-Replace the current top header/banner/dropdown workflow with a centered tool pager directly above Editors.
+Rollback anchor:
+Find the commit with commit comment:
+Remove Workspace Manager default and query fallbacks
 
-Required behavior:
-- URL tools/Workspace Manager/index.html?gameId=Bouncing-ball&mount=game renders existing Workspace Manager page shell.
-- Remove newly created top banner/header/control content.
-- Directly above Editors, centered, render:
-  [PREV] <selected tool name> [NEXT]
-- On page load, select the first available tool for the explicit gameId context.
-- Activate/mount selected tool on page load.
-- Prev/Next changes the selected tool and active/mounted tool.
-- Do not require dropdown.
-- Do not require Select Tool button.
-- Do not require Mount button.
-- Keep game context loaded from explicit gameId.
-- Keep samples untouched.
+This is the state after BUILD_PR_LEVEL_20_13_REMOVE_WORKSPACE_MANAGER_DEFAULT_AND_QUERY_FALLBACKS and before the failed 20_14 through 20_19 header/banner attempts.
 
-User-approved exception:
-- First available tool selected on page load is REQUIRED for this PR.
-- This is not considered fallback/default anti-pattern for this PR.
+Required steps:
+1. Inspect git history for Workspace Manager files.
+2. Restore only Workspace Manager files affected by 20_14 through 20_19 to the rollback anchor state.
+   Likely files:
+   - tools/Workspace Manager/main.js
+   - tools/Workspace Manager/index.html
+   - any Workspace Manager CSS touched by those PRs
+3. Do not rollback unrelated files.
+4. After restore, add exactly one centered pager directly above the existing tools/editors section:
+   [PREV] <toolname> [NEXT]
+5. On page load, select the first available tool for the explicit gameId context.
+6. Mount/activate that selected tool.
+7. Prev/Next changes selected and mounted tool.
+8. Do not use dropdown + Select Tool + Mount workflow.
+9. Do not create or keep any new header/banner.
 
 Still forbidden:
-- restoring gameId || game
+- restore gameId || game
 - legacy game query fallback
 - hidden fallback routing
 - stale memory reuse
-- new header/banner
+- changing samples
 - broad Workspace Manager refactor
-- second SSoT
 - start_of_day changes
 
-Likely files:
-- tools/Workspace Manager/main.js
-- tools/Workspace Manager/index.html
-- Workspace Manager CSS only if needed
-
 Validation:
-Create docs/dev/reports/workspace_manager_tool_pager_above_editors_validation.md with:
+Create docs/dev/reports/workspace_manager_rollback_header_and_tool_pager_validation.md with:
+- rollback anchor commit hash and comment
 - changed files
-- proof newly created header/banner/control area removed
-- proof centered [PREV] <toolname> [NEXT] appears above Editors
-- proof first available tool selected on page load
-- proof selected tool active/mounted on page load
+- proof failed header/banner/control area removed
+- proof normal Workspace Manager content loads below site chrome
+- proof only [PREV] <toolname> [NEXT] was added
+- proof pager appears above existing tools/editors section
+- proof first available tool selected/mounted on load
 - proof Prev/Next changes selected/mounted tool
-- proof dropdown + Select Tool + Mount initial workflow removed
 - proof gameId || game fallback not restored
-- proof game context still loads from explicit gameId
-- proof sample Open <tool> remains untouched
+- proof samples remain untouched
 - anti-pattern self-check
 
 Return ZIP at:
-tmp/BUILD_PR_LEVEL_20_19_FORCE_WORKSPACE_TOOL_PAGER_ABOVE_EDITORS.zip
+tmp/BUILD_PR_LEVEL_20_20_ROLLBACK_WORKSPACE_HEADER_AND_ADD_TOOL_PAGER.zip
 ```

docs/operations/dev/commit_comment.txt

@@ -1,9 +1,8 @@
-Force Workspace Manager tool pager above Editors
+Rollback Workspace Manager header attempts and add tool pager
 
 PR Details:
-- Removes the newly created Workspace Manager top header/banner workflow.
-- Adds centered [PREV] <toolname> [NEXT] control above Editors.
-- Selects and mounts the first available tool on page load per user direction.
-- Prev/Next switches selected and mounted tool.
-- Removes dropdown + Select Tool + Mount initial workflow.
-- Keeps explicit gameId and does not restore legacy query fallback.
+- Restores Workspace Manager layout from the pre-header/banner anchor.
+- Removes failed top Workspace Manager header/banner/control experiments.
+- Adds centered [PREV] <toolname> [NEXT] above the existing tools/editors section.
+- Selects and mounts the first available tool on load.
+- Keeps explicit gameId behavior without restoring legacy query fallback.