* Swap to feature workspace + UTF-8 stdout fix for workspace_swap

scripts/workspace_swap.py:
- Force UTF-8 reconfigure on sys.stdout/sys.stderr at module load.
  Without this, the Unicode box-drawing characters used in section
  headers and the summary banner crash on Windows consoles that default
  to cp1252. Surfaced when running --dry-run end-to-end for the first
  time.

data/fabric (workspace_swap output for branch test-workspace-swap-changes):
- New per-branch value set: Patterns_Variables.VariableLibrary/valueSets/
  test-workspace-swap-changes.json
- settings.json valueSetsOrder updated
- Patterns_Semantic_Model.SemanticModel: Direct Lake URL repointed
- Import_Patterns_Data.Notebook: META block lakehouse dependency
  repointed

* Update

* Harden workspace_swap: mandatory .env, YES confirmation, self-heal recovery

Surfaced by a real-world incident where stale .env values produced a
swap pointed at the wrong workspace and the script's one-way find/replace
couldn't recover from the resulting bad state.

scripts/workspace_swap.py changes:

1. resolve_feature_ids() now requires .env. Removes the value-set-priority
   path and the interactive-prompt fallback. Both were silently overriding
   what the developer typed in .env. Missing .env, missing keys, or blank
   values \u2192 sys.exit() with a clear error pointing at .env.sample.

2. New _confirm_swap_to_feature() helper. Prints a 'Planned swap' summary
   showing dev \u2192 feature for both workspace and lakehouse, then requires
   the user to type literal 'YES' (case-sensitive, exact match). Anything
   else \u2192 abort cleanly. Skipped on --dry-run since the dry-run is itself
   the verification step.

3. New _read_previous_feature_ids() helper + recovery pass in
   _run_swap_to_feature(). Reads the previously-applied feature IDs from
   the per-branch value-set file BEFORE the value set is rewritten in
   step 3, then runs a second find/replace pass in step 4 to rewrite any
   stale feature IDs that remain in repointable files. Skipped when the
   previous IDs match the target (no recovery needed) or when there's no
   previous record (first swap).

4. --check-ready and --swap-to-dev are unaffected. swap-to-dev still
   reads from the value-set file as the source of feature IDs.

tests/test_workspace_swap.py changes:

- Removed the value-set-priority and prompt-fallback tests
- Added 7 strict 'exits cleanly' tests for resolve_feature_ids
- New TestConfirmSwapToFeature class: 7 tests covering YES /
  lowercase / blank / EOF / whitespace / planned-summary-display
- New TestReadPreviousFeatureIds class: 4 tests covering the helper
- Wrapped existing _run_swap_to_feature test calls in YES input mock
- Added test_dry_run_skips_confirmation
- Added test_recovers_from_stale_feature_ids_in_files (regression
  guard for today's incident)
- Added test_no_recovery_pass_when_stale_matches_target

Verified: 185 tests pass (was 173).

* Fix corrupted feature IDs in SemanticModel + Notebook (manual recovery)

The first run of workspace_swap on this branch (commit 9aebf8f) was
driven by stale .env values, applying the wrong workspace ID
(613e22cd-308a-4106-9745-58bd5164568a) and the wrong lakehouse ID
(1b80046f-d76e-4748-acfc-575f3fbd23f4) into:
  - Patterns_Semantic_Model.SemanticModel/definition/expressions.tmdl
  - Import_Patterns_Data.Notebook/notebook-content.py

The Fabric UI subsequently corrected the value-set file (commit 7f7ac85),
which severed the breadcrumb the new self-heal recovery pass uses to
discover stale IDs. So the recovery pass can't help with this specific
state \u2014 the fix is manual.

Replaces:
  613e22cd-308a-4106-9745-58bd5164568a \u2192 1484d4b0-4c88-4347-9cce-2d2bd03848b0
  1b80046f-d76e-4748-acfc-575f3fbd23f4 \u2192 914bb153-d687-4ea9-9870-d61434b2884f

Also normalizes the trailing newline in the value-set file (added by
the script's JSON serializer; cosmetic).

After this commit, all .env GUIDs match what's in the tracked Fabric
files. Going forward, the script's confirmation prompt + self-heal
recovery will catch this class of incident automatically.

* Ghost

* Swap back to dev for PR readiness

Reverts the test-workspace-swap-changes branch to dev IDs ahead of opening
the PR to dev. The check-pr-ready CI workflow enforces this — feature IDs
in tracked Fabric files would block the merge.

Reverted by scripts/workspace_swap.py --swap-to-dev:
- Patterns_Semantic_Model.SemanticModel/definition/expressions.tmdl
  (Direct Lake URL: feature → dev)
- Import_Patterns_Data.Notebook/notebook-content.py
  (META block: feature → dev)
- Patterns_Variables.VariableLibrary/valueSets/test-workspace-swap-changes.json
  (deleted — per-branch value set no longer needed)
- Patterns_Variables.VariableLibrary/settings.json
  (test-workspace-swap-changes removed from valueSetsOrder)

* Swap to feature workspace + chat-driven confirmation in prompt

Test of the updated swap-to-feature.prompt.md flow that moves the YES
confirmation into the chat UI instead of a live terminal prompt.

scripts/workspace_swap.py output for branch swap-file-smoke-test:
- New per-branch value set: Patterns_Variables.VariableLibrary/valueSets/
  swap-file-smoke-test.json
- settings.json valueSetsOrder updated
- Patterns_Semantic_Model.SemanticModel: Direct Lake URL repointed to
  feature workspace + lakehouse
- Import_Patterns_Data.Notebook: META block lakehouse dependency
  repointed to feature workspace + lakehouse

.github/prompts/swap-to-feature.prompt.md updated to instruct the agent
to ask for confirmation in the chat UI (vscode_askQuestions) and then
pipe YES into the script (echo "YES" | python ...) so the terminal
never blocks on the script's interactive Confirm: prompt.

* Swap back to dev for PR readiness

Reverts the swap-file-smoke-test branch to dev IDs ahead of opening
the PR to dev. The check-pr-ready CI workflow enforces this — feature
IDs in tracked Fabric files would block the merge.

Reverted by scripts/workspace_swap.py --swap-to-dev:
- Patterns_Semantic_Model.SemanticModel/definition/expressions.tmdl
  (Direct Lake URL: feature → dev)
- Import_Patterns_Data.Notebook/notebook-content.py
  (META block: feature → dev)
- Patterns_Variables.VariableLibrary/valueSets/swap-file-smoke-test.json
  (deleted — per-branch value set no longer needed)
- Patterns_Variables.VariableLibrary/settings.json
  (swap-file-smoke-test removed from valueSetsOrder)

… pass (#36)

PR #34 made .env mandatory for swap-to-feature, removed the interactive
prompt fallback, removed the value-set-priority shortcut, and added a
case-sensitive YES confirmation. PR #35 moved that confirmation into the
chat UI for slash-command invocations. fabric-development-process.md still
described the old behavior in three spots.

Updates:
- Step 4 (swap-to-feature): drop the 'or prompts if .env is missing'
  claim; add the YES confirmation step; add the recovery pass step.
- Local .env Setup section: replace 'falls back to interactive prompt'
  + 'value set is source of truth' with the new model (.env always
  authoritative for swap-to-feature; value set used by swap-to-dev
  and the recovery pass; YES confirmation gate).
- Copilot Chat section: note that /swap-to-feature moves the YES
  confirmation into the chat UI.

Tests: 185 pass (no script changes).