diff --git a/agent/redact.py b/agent/redact.py
index 7cf0a49daf..2bd631228e 100644
--- a/agent/redact.py
+++ b/agent/redact.py
@@ -230,8 +230,11 @@ _ENV_ASSIGN_LOWER_RE = re.compile(
 # bare secret-word key only at line start (optionally after ``export``), so conversational ``I have
 # password=foo`` mid-sentence is left alone.
 _SECRET_CFG_NAMES = r"(?:api[ _.\-]?key|token|secret|passwd|password|credential|auth)"
-# Rendered line-number prefix (``5|line`` from read_file, ``6:line`` from grep -n / cat -n).
-_LINE_NUMBER_GUTTER = r"[0-9]+[|:][ \t]*"
+# Rendered line-number prefix: ``5|line`` (read_file), ``6:line`` (grep -n), ``7-line`` (grep -A/-B/-C
+# context lines) and ``     8\tline`` (cat -n / nl: right-aligned number + TAB). Callers put the ONLY
+# leading ``[ \t]*`` in front of it — stacking a second whitespace run around an optional gutter made
+# the anchored passes quadratic on long indented lines (2s per 5k spaces).
+_LINE_NUMBER_GUTTER = r"(?:[0-9]+(?:[|:\-]|\t)[ \t]*)?"
 _CFG_VALUE = r"(['\"]?)([^\s&]+?)\2(?=[\s&]|$)"
 # Linear pre-gate for the _CFG_*_RE subs: no secret keyword => neither can match.
 _CFG_SECRET_WORD_RE = re.compile(_SECRET_CFG_NAMES, re.IGNORECASE)
@@ -253,11 +256,11 @@ _CFG_DOTTED_RE = re.compile(
 )
 # Line-anchored bare key: ``password=…`` / ``export api_key=…`` at start of line.
 # ``{_LINE_NUMBER_GUTTER}``: line-numbered dumps put the key behind a rendered gutter —
-# ``read_file`` emits ``5|      ADS_API_TOKEN: …`` and ``grep -n`` / ``cat -n`` emit
-# ``6:      ADS_API_TOKEN: …``. Anchored at ``^`` without it, none of those matched, so the
-# rendered read of a secret-bearing file leaked what the raw text masked.
+# ``read_file`` emits ``5|      ADS_API_TOKEN: …``, ``grep -n`` emits ``6:      ADS_API_TOKEN: …``
+# and ``cat -n`` emits ``     7\tADS_API_TOKEN: …``. Anchored at ``^`` without it, none of those
+# matched, so the rendered read of a secret-bearing file leaked what the raw text masked.
 _CFG_ANCHORED_RE = re.compile(
-    rf"(^(?:[ \t]*{_LINE_NUMBER_GUTTER})?[ \t]*(?:export[ \t]+)?[A-Za-z0-9_\-]*{_SECRET_CFG_NAMES}[A-Za-z0-9_\-]*)={_CFG_VALUE}",
+    rf"(^[ \t]*{_LINE_NUMBER_GUTTER}(?:export[ \t]+)?[A-Za-z0-9_\-]*{_SECRET_CFG_NAMES}[A-Za-z0-9_\-]*)={_CFG_VALUE}",
     re.IGNORECASE | re.MULTILINE,
 )
 
@@ -270,7 +273,7 @@ _CFG_ANCHORED_RE = re.compile(
 # stays backtrackable (see _CFG_DOTTED_RE).
 _YAML_CFG_NAMES = r"(?:api[ _.\-]?key|token|secret|passwd|password|credential)"
 _YAML_ASSIGN_RE = re.compile(
-    rf"(^(?:[ \t]*+{_LINE_NUMBER_GUTTER})?[ \t]*+[A-Za-z0-9_.\-]*{_YAML_CFG_NAMES}[A-Za-z0-9_.\-]*+)(:[ \t]*+)(?!['\"])([^\s&]++)",
+    rf"(^[ \t]*+{_LINE_NUMBER_GUTTER}[A-Za-z0-9_.\-]*{_YAML_CFG_NAMES}[A-Za-z0-9_.\-]*+)(:[ \t]*+)(?!['\"])([^\s&]++)",
     re.IGNORECASE | re.MULTILINE,
 )
 
@@ -305,6 +308,11 @@ _STRONG_KEY_KEYWORD_RE = re.compile(
     r"|key[ _.\\-]?material|secret|passwd|password|pass|pw|credential|auth|bearer",
     re.IGNORECASE,
 )
+# Password-class keys mask any literal value; for other keys a value that starts like ``$HOME/...``,
+# ``/usr/...`` or ``~/...`` references a variable or a path, not a credential, even under a strong key
+# (``SSH_AUTH_SOCK=$HOME/.ssh/agent.sock``, ``DOCKER_AUTH_CONFIG=/home/u/.docker``).
+_PASSWORD_KEY_RE = re.compile(r"passwd|password|pass|pw", re.IGNORECASE)
+_PATH_OR_VAR_VALUE_RE = re.compile(r"[$/~]")
 
 
 def _is_word_start(s: str, i: int) -> bool:
@@ -370,6 +378,10 @@ def _should_redact_assignment(key: str, value: str, *, check_keyword: bool) -> b
         return False
     if check_keyword and not _key_has_secret_keyword(key):
         return False
+    # A shell rc's ``SSH_AUTH_SOCK=$HOME/.ssh/agent.sock`` is configuration the agent must keep
+    # readable; only password-class keys mask a path/variable reference.
+    if _PATH_OR_VAR_VALUE_RE.match(value) and not _has_word_bounded_keyword(key, _PASSWORD_KEY_RE):
+        return False
     return (_has_word_bounded_keyword(key, _STRONG_KEY_KEYWORD_RE)
             or _looks_like_opaque_credential(value))
 
@@ -1030,7 +1042,7 @@ def _is_secret_file_arg(arg: str) -> bool:
         return True
     # ``config.yaml`` plus the ``config.yaml.good.<stamp>`` / ``.corrupt.<stamp>`` copies Hermes
     # writes under ``backups/config/`` — same contents, same secrets.
-    if parts[-1] != "config.yaml" and not parts[-1].startswith("config.yaml."):
+    if parts[-1] != "config.yaml" and not parts[-1].startswith(("config.yaml.good.", "config.yaml.corrupt.")):
         return False
     return hermes_home or ".hermes" in parts[:-1] or _is_under_hermes_home(path)
 
diff --git a/tests/agent/test_redact.py b/tests/agent/test_redact.py
index ca402dcc63..f7cd435e1b 100644
--- a/tests/agent/test_redact.py
+++ b/tests/agent/test_redact.py
@@ -2,6 +2,7 @@
 
 import ast
 import logging
+import time
 
 import pytest
 
@@ -1259,7 +1260,10 @@ class TestSecretFileAssignmentRedaction:
         ("FOO_API_KEY={tok}", "«redacted-secret»"),             # dotenv
         ('{{"api_key": "{tok}"}}', "«redacted-secret»"),        # JSON
         ("5|      ADS_API_TOKEN: {tok}", "«redacted-secret»"),  # read_file line gutter
-        ("108:ADS_API_TOKEN: {tok}", "«redacted-secret»"),      # grep -n / cat -n gutter
+        ("108:ADS_API_TOKEN: {tok}", "«redacted-secret»"),      # grep -n gutter
+        ("108-      ADS_API_TOKEN: {tok}", "«redacted-secret»"),  # grep -A/-B/-C context gutter
+        ("   108\tADS_API_TOKEN: {tok}", "«redacted-secret»"),   # cat -n / nl gutter (number + TAB)
+        ("   108\texport FOO_TOKEN={tok}", "«redacted-secret»"),
         ("GITHUB_TOKEN: ghp_S1abcdefghijklmnopqrstuvwxyz0Pn2T", "«redacted:ghp_…»"),  # prefix label kept
     ])
     def test_secret_file_masks_assignment_with_non_reusable_sentinel(self, template, sentinel):
@@ -1272,9 +1276,17 @@ class TestSecretFileAssignmentRedaction:
     def test_unclassified_read_and_non_secret_scalars_are_untouched(self):
         for text in ("MAX_TOKENS: 100", '{"apiKey": "test"}', "api_key: test", f"5|ADS_API_TOKEN: {self.SYNTH}"):
             assert redact_sensitive_text(text, force=True, file_read=True) == text
-        out = redact_sensitive_text(f"ADS_API_TOKEN: {self.SYNTH}\n5|MAX_TOKENS: 100\n", force=True,
-                                    file_read=True, secret_file=True)
-        assert self.SYNTH not in out and "5|MAX_TOKENS: 100" in out
+        # Strong-key names whose value is a variable/path reference are shell-rc configuration, not
+        # secrets; the agent must still be able to read and edit them (password-class keys mask anyway).
+        rc = "export SSH_AUTH_SOCK=$HOME/.ssh/agent.sock\nexport DOCKER_AUTH_CONFIG=/home/u/.docker\n"
+        out = redact_sensitive_text(rc + f"ADS_API_TOKEN: {self.SYNTH}\n5|MAX_TOKENS: 100\nDB_PASSWORD=~/pw\n",
+                                    force=True, file_read=True, secret_file=True)
+        assert out.startswith(rc) and self.SYNTH not in out and "5|MAX_TOKENS: 100" in out and "~/pw" not in out
+        # The gutter-tolerant anchors must stay linear: a wide indented line is not a stall.
+        wide = "1|" + " " * 20000 + "token:"
+        started = time.perf_counter()
+        assert redact_sensitive_text(wide, force=True, file_read=True, secret_file=True) == wide
+        assert time.perf_counter() - started < 1.0
 
 
 class TestHermesHomePathClassification:
@@ -1292,6 +1304,7 @@ class TestHermesHomePathClassification:
         assert _is_secret_file_arg(str(home / "config.yaml"))
         assert _is_secret_file_arg(str(home / "profiles" / "coder" / "config.yaml"))
         assert _is_secret_file_arg(str(home / "backups" / "config" / "config.yaml.good.20260914-184559"))
+        assert not _is_secret_file_arg(str(home / "config.yaml.pdf"))  # only the backups/config/ copies
         assert not _is_secret_file_arg(str(tmp_path / "proj" / "config.yaml"))
         assert not _is_secret_file_arg("config.yaml")  # relative, not resolvable to the home