diff --git a/learning-room/.github/workflows/autograder-capstone.yml b/learning-room/.github/workflows/autograder-capstone.yml
index a58111c..c77e8be 100644
--- a/learning-room/.github/workflows/autograder-capstone.yml
+++ b/learning-room/.github/workflows/autograder-capstone.yml
@@ -14,6 +14,10 @@ permissions:
   contents: read
   pull-requests: write
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   validate-agent:
     name: Verify Agent File
@@ -28,44 +32,42 @@ jobs:
         run: |
           # Find new/modified .md files in agents/ or community-agents/
           AGENTS=$(find agents community-agents -name '*.md' 2>/dev/null || true)
-
+          
           if [ -z "$AGENTS" ]; then
             echo "found=false" >> "$GITHUB_OUTPUT"
             exit 0
           fi
-
+          
           echo "found=true" >> "$GITHUB_OUTPUT"
           FIRST=$(echo "$AGENTS" | head -1)
           echo "file=$FIRST" >> "$GITHUB_OUTPUT"
-          CHECK_FILE="/tmp/capstone-agent.md"
-          sed '1s/^\xEF\xBB\xBF//' "$FIRST" > "$CHECK_FILE"
-
+          
           ERRORS=""
-
+          
           # Check YAML frontmatter exists (starts with ---)
-          if head -1 "$CHECK_FILE" | grep -q '^---'; then
+          if head -1 "$FIRST" | grep -q '^---'; then
             echo "has_frontmatter=true" >> "$GITHUB_OUTPUT"
           else
             echo "has_frontmatter=false" >> "$GITHUB_OUTPUT"
             ERRORS="missing YAML frontmatter"
           fi
-
+          
           # Check for responsibilities section
-          if grep -qi '## responsibilities\|## what this agent does' "$CHECK_FILE"; then
+          if grep -qi '## responsibilities\|## what this agent does' "$FIRST"; then
             echo "has_responsibilities=true" >> "$GITHUB_OUTPUT"
           else
             echo "has_responsibilities=false" >> "$GITHUB_OUTPUT"
             ERRORS="$ERRORS${ERRORS:+, }missing responsibilities section"
           fi
-
+          
           # Check for guardrails section
-          if grep -qi '## guardrails\|## limitations\|## boundaries' "$CHECK_FILE"; then
+          if grep -qi '## guardrails\|## limitations\|## boundaries' "$FIRST"; then
             echo "has_guardrails=true" >> "$GITHUB_OUTPUT"
           else
             echo "has_guardrails=false" >> "$GITHUB_OUTPUT"
             ERRORS="$ERRORS${ERRORS:+, }missing guardrails section"
           fi
-
+          
           echo "errors=$ERRORS" >> "$GITHUB_OUTPUT"
 
       - name: Post result
@@ -105,13 +107,70 @@ jobs:
                 'Excellent capstone work!'
               ].join('\n');
             }
+            const MARKER = '## Challenge 16:';
             try {
-              await github.rest.issues.createComment({
+              const { data: comments } = await github.rest.issues.listComments({
                 owner: context.repo.owner,
                 repo: context.repo.repo,
-                issue_number: context.issue.number,
-                body
+                issue_number: context.issue.number
               });
+              const existing = comments.find(c => c.user.type === 'Bot' && c.body.includes(MARKER));
+              if (existing) {
+                await github.rest.issues.updateComment({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  comment_id: existing.id,
+                  body
+                });
+              } else {
+                await github.rest.issues.createComment({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  issue_number: context.issue.number,
+                  body
+                });
+              }
             } catch (error) {
               console.error('Could not post Challenge 16 result:', error.message);
             }
+
+      - name: Post workflow error notice
+        if: failure()
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const MARKER = '## Challenge 16:';
+            const body = [
+              '## Challenge 16: Check could not complete',
+              '',
+              'The automated agent file check ran into an unexpected error. Your work is not affected.',
+              'Keep going and ask your facilitator, or mention @facilitator in a comment.',
+              '',
+              '---',
+              '*Automated message from Learning Room Bot.*'
+            ].join('\n');
+            try {
+              const { data: comments } = await github.rest.issues.listComments({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: context.issue.number
+              });
+              const existing = comments.find(c => c.user.type === 'Bot' && c.body.includes(MARKER));
+              if (existing) {
+                await github.rest.issues.updateComment({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  comment_id: existing.id,
+                  body
+                });
+              } else {
+                await github.rest.issues.createComment({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  issue_number: context.issue.number,
+                  body
+                });
+              }
+            } catch (err) {
+              console.error('Could not post error notice:', err.message);
+            }
diff --git a/learning-room/.github/workflows/autograder-conflicts.yml b/learning-room/.github/workflows/autograder-conflicts.yml
index 1749172..bb8985f 100644
--- a/learning-room/.github/workflows/autograder-conflicts.yml
+++ b/learning-room/.github/workflows/autograder-conflicts.yml
@@ -11,6 +11,10 @@ permissions:
   contents: read
   pull-requests: write
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   check-conflict-markers:
     name: Verify Conflict Resolution
@@ -75,13 +79,70 @@ jobs:
                 'No conflict markers found and the file has substantive content. Well done!'
               ].join('\n');
             }
+            const MARKER = '## Challenge 7:';
             try {
-              await github.rest.issues.createComment({
+              const { data: comments } = await github.rest.issues.listComments({
                 owner: context.repo.owner,
                 repo: context.repo.repo,
-                issue_number: context.issue.number,
-                body
+                issue_number: context.issue.number
               });
+              const existing = comments.find(c => c.user.type === 'Bot' && c.body.includes(MARKER));
+              if (existing) {
+                await github.rest.issues.updateComment({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  comment_id: existing.id,
+                  body
+                });
+              } else {
+                await github.rest.issues.createComment({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  issue_number: context.issue.number,
+                  body
+                });
+              }
             } catch (error) {
               console.error('Could not post Challenge 7 result:', error.message);
             }
+
+      - name: Post workflow error notice
+        if: failure()
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const MARKER = '## Challenge 7:';
+            const body = [
+              '## Challenge 7: Check could not complete',
+              '',
+              'The automated conflict marker check ran into an unexpected error. Your work is not affected.',
+              'Keep going and ask your facilitator, or mention @facilitator in a comment.',
+              '',
+              '---',
+              '*Automated message from Learning Room Bot.*'
+            ].join('\n');
+            try {
+              const { data: comments } = await github.rest.issues.listComments({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: context.issue.number
+              });
+              const existing = comments.find(c => c.user.type === 'Bot' && c.body.includes(MARKER));
+              if (existing) {
+                await github.rest.issues.updateComment({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  comment_id: existing.id,
+                  body
+                });
+              } else {
+                await github.rest.issues.createComment({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  issue_number: context.issue.number,
+                  body
+                });
+              }
+            } catch (err) {
+              console.error('Could not post error notice:', err.message);
+            }
diff --git a/learning-room/.github/workflows/autograder-local-commit.yml b/learning-room/.github/workflows/autograder-local-commit.yml
index a3e7f51..cbfa0d9 100644
--- a/learning-room/.github/workflows/autograder-local-commit.yml
+++ b/learning-room/.github/workflows/autograder-local-commit.yml
@@ -11,6 +11,10 @@ permissions:
   contents: read
   pull-requests: write
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   check-local-commit:
     name: Verify Local Commit Exists
@@ -66,13 +70,70 @@ jobs:
                 'Your local Git workflow is working. Well done!'
               ].join('\n');
             }
+            const MARKER = '## Challenge 10:';
             try {
-              await github.rest.issues.createComment({
+              const { data: comments } = await github.rest.issues.listComments({
                 owner: context.repo.owner,
                 repo: context.repo.repo,
-                issue_number: context.issue.number,
-                body
+                issue_number: context.issue.number
               });
+              const existing = comments.find(c => c.user.type === 'Bot' && c.body.includes(MARKER));
+              if (existing) {
+                await github.rest.issues.updateComment({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  comment_id: existing.id,
+                  body
+                });
+              } else {
+                await github.rest.issues.createComment({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  issue_number: context.issue.number,
+                  body
+                });
+              }
             } catch (error) {
               console.error('Could not post Challenge 10 result:', error.message);
             }
+
+      - name: Post workflow error notice
+        if: failure()
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const MARKER = '## Challenge 10:';
+            const body = [
+              '## Challenge 10: Check could not complete',
+              '',
+              'The automated local commit check ran into an unexpected error. Your work is not affected.',
+              'Keep going and ask your facilitator, or mention @facilitator in a comment.',
+              '',
+              '---',
+              '*Automated message from Learning Room Bot.*'
+            ].join('\n');
+            try {
+              const { data: comments } = await github.rest.issues.listComments({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: context.issue.number
+              });
+              const existing = comments.find(c => c.user.type === 'Bot' && c.body.includes(MARKER));
+              if (existing) {
+                await github.rest.issues.updateComment({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  comment_id: existing.id,
+                  body
+                });
+              } else {
+                await github.rest.issues.createComment({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  issue_number: context.issue.number,
+                  body
+                });
+              }
+            } catch (err) {
+              console.error('Could not post error notice:', err.message);
+            }
diff --git a/learning-room/.github/workflows/autograder-template.yml b/learning-room/.github/workflows/autograder-template.yml
index 57a490c..54336b6 100644
--- a/learning-room/.github/workflows/autograder-template.yml
+++ b/learning-room/.github/workflows/autograder-template.yml
@@ -11,6 +11,10 @@ permissions:
   contents: read
   pull-requests: write
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   check-template:
     name: Verify Custom Issue Template
@@ -28,28 +32,25 @@ jobs:
             ! -name 'challenge-*.yml' \
             ! -name 'bonus-*.yml' \
             ! -name 'config.yml' 2>/dev/null || true)
-
+          
           if [ -z "$TEMPLATES" ]; then
             echo "found=false" >> "$GITHUB_OUTPUT"
             exit 0
           fi
-
+          
           echo "found=true" >> "$GITHUB_OUTPUT"
-
-          # Check the first custom template for a name field.
-          # Normalize a UTF-8 BOM because Windows tooling may add one.
+          
+          # Check the first custom template for a name field
           FIRST=$(echo "$TEMPLATES" | head -1)
           echo "file=$FIRST" >> "$GITHUB_OUTPUT"
-          CHECK_FILE="/tmp/custom-issue-template.yml"
-          sed '1s/^\xEF\xBB\xBF//' "$FIRST" > "$CHECK_FILE"
-
-          if grep -q '^name:' "$CHECK_FILE"; then
+          
+          if grep -q '^name:' "$FIRST"; then
             echo "has_name=true" >> "$GITHUB_OUTPUT"
           else
             echo "has_name=false" >> "$GITHUB_OUTPUT"
           fi
-
-          if grep -q '^description:' "$CHECK_FILE"; then
+          
+          if grep -q '^description:' "$FIRST"; then
             echo "has_desc=true" >> "$GITHUB_OUTPUT"
           else
             echo "has_desc=false" >> "$GITHUB_OUTPUT"
@@ -92,13 +93,70 @@ jobs:
                 'Found `' + file + '` with valid `name` and `description` fields. Well done!'
               ].join('\n');
             }
+            const MARKER = '## Challenge 14:';
             try {
-              await github.rest.issues.createComment({
+              const { data: comments } = await github.rest.issues.listComments({
                 owner: context.repo.owner,
                 repo: context.repo.repo,
-                issue_number: context.issue.number,
-                body
+                issue_number: context.issue.number
               });
+              const existing = comments.find(c => c.user.type === 'Bot' && c.body.includes(MARKER));
+              if (existing) {
+                await github.rest.issues.updateComment({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  comment_id: existing.id,
+                  body
+                });
+              } else {
+                await github.rest.issues.createComment({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  issue_number: context.issue.number,
+                  body
+                });
+              }
             } catch (error) {
               console.error('Could not post Challenge 14 result:', error.message);
             }
+
+      - name: Post workflow error notice
+        if: failure()
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const MARKER = '## Challenge 14:';
+            const body = [
+              '## Challenge 14: Check could not complete',
+              '',
+              'The automated issue template check ran into an unexpected error. Your work is not affected.',
+              'Keep going and ask your facilitator, or mention @facilitator in a comment.',
+              '',
+              '---',
+              '*Automated message from Learning Room Bot.*'
+            ].join('\n');
+            try {
+              const { data: comments } = await github.rest.issues.listComments({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: context.issue.number
+              });
+              const existing = comments.find(c => c.user.type === 'Bot' && c.body.includes(MARKER));
+              if (existing) {
+                await github.rest.issues.updateComment({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  comment_id: existing.id,
+                  body
+                });
+              } else {
+                await github.rest.issues.createComment({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  issue_number: context.issue.number,
+                  body
+                });
+              }
+            } catch (err) {
+              console.error('Could not post error notice:', err.message);
+            }
diff --git a/learning-room/.github/workflows/autograder-watchdog.yml b/learning-room/.github/workflows/autograder-watchdog.yml
new file mode 100644
index 0000000..e5e77a0
--- /dev/null
+++ b/learning-room/.github/workflows/autograder-watchdog.yml
@@ -0,0 +1,99 @@
+name: Autograder Failure Watchdog
+# Last-resort safety net for classroom reliability.
+# Fires after any autograder workflow completes with conclusion=failure.
+# If the in-job error handler already posted a comment, this is a no-op.
+# If not (e.g. the runner was abandoned before the fallback step ran),
+# this posts a friendly message to the student's PR so they never see silence.
+
+on:
+  workflow_run:
+    workflows:
+      - "Challenge 7: Merge Conflict Resolution Check"
+      - "Challenge 10: Local Commit Check"
+      - "Challenge 14: Issue Template Validation"
+      - "Challenge 16: Capstone Agent File Validation"
+    types: [completed]
+
+permissions:
+  pull-requests: write
+
+jobs:
+  notify-on-failure:
+    name: Post friendly notice if job failed silently
+    runs-on: ubuntu-latest
+    # Only act on hard failures, not cancellations (concurrency group cancels are expected).
+    if: github.event.workflow_run.conclusion == 'failure'
+
+    steps:
+      - name: Find PR and post notice if needed
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const run = context.payload.workflow_run;
+            const workflowName = run.name;
+            const headBranch   = run.head_branch;
+            const runCreatedAt = new Date(run.created_at);
+
+            const { data: prs } = await github.rest.pulls.list({
+              owner: context.repo.owner,
+              repo:  context.repo.repo,
+              state: 'open',
+              head:  `${context.repo.owner}:${headBranch}`
+            });
+
+            if (prs.length === 0) {
+              console.log('No open PR found for branch:', headBranch);
+              return;
+            }
+
+            const pr = prs[0];
+
+            const { data: comments } = await github.rest.issues.listComments({
+              owner:        context.repo.owner,
+              repo:         context.repo.repo,
+              issue_number: pr.number
+            });
+
+            const challengeMarkers = [
+              '## Challenge 7:',
+              '## Challenge 10:',
+              '## Challenge 14:',
+              '## Challenge 16:'
+            ];
+
+            const alreadyPosted = comments.some(c =>
+              c.user.type === 'Bot' &&
+              new Date(c.updated_at) > runCreatedAt &&
+              challengeMarkers.some(m => c.body.includes(m))
+            );
+
+            if (alreadyPosted) {
+              console.log('Result already posted by in-job handler -- watchdog is a no-op.');
+              return;
+            }
+
+            const m = workflowName.match(/Challenge (\d+)/);
+            const num = m ? m[1] : '?';
+
+            const body = [
+              `## Challenge ${num}: Check could not complete`,
+              '',
+              `The automated check ran into an unexpected problem on our end. Your work is not affected.`,
+              '',
+              'Keep going and let your facilitator know, or leave a comment mentioning @facilitator.',
+              '',
+              '---',
+              '*Automated message from Learning Room Bot.*'
+            ].join('\n');
+
+            try {
+              await github.rest.issues.createComment({
+                owner:        context.repo.owner,
+                repo:         context.repo.repo,
+                issue_number: pr.number,
+                body
+              });
+              console.log(`Watchdog posted notice on PR #${pr.number}`);
+            } catch (err) {
+              console.error('Watchdog could not post notice:', err.message);
+            }
\ No newline at end of file